The Human Factor in the 'Unmanned' Systems of the People's Liberation Army

This essay is part of the #WarBots series, which asked a group of academics and national security professionals to provide their thoughts on the confluence of automation and unmanned technologies and their impact in the conduct of war. We hope this launches a debate that may one day shape policy.

Zhao Xu and His Scientific Team

As China progressed in the development and fielding of UAVs, the PLA started to establish educational and training programs for UAV operators across the services, reflecting recognition of the importance of personnel. In 1994, the PLA created its first course for cadets at the Army Artillery Academy to train as UAV operators and technicians, who could go on to leverage UAVs for battlefield reconnaissance, target positioning, and damage assessment.[14] There have been nearly a dozen PLA academic institutions, such as the PLA Air Force Engineering University, that provide education and training for future UAV officers and enlisted specialists.[15] For example, the PLA’s Naval Aviation Engineering Academy has instructed the technical officer cadre for assault UAVs.[16] It is difficult to determine the level of sophistication of the instruction that students in these programs receive. There are references to students at the Ordnance Engineering College engaging in training with UAVs that included launch, remote control, and real-time image acquisition.[17] Beyond formal educational programs, there are also specialized courses available to officers and enlisted personnel, and certain units have organized training exercises focused on advancing operational capabilities, often training to engage in battlefield reconnaissance and electronic countermeasures.[18]

While creating these educational and training programs for UAV operators, the PLA has also progressed towards formalizing and standardizing training with UAVs. In 2001, the PLA drafted its first “UAV Outline of Military Training and Evaluation” (UAV OMTE, æ? ?æ?º?ç»?ä¸?è?????).[19] Although there are no details available about the contents of this OMTE, PLA OMTE generally offer guidance for training, including goals, principles, and content, as well as implementation phases and procedures, and often require several years to draft and revise.[20,21] The development of a formal curriculum for UAV operational units at that surprisingly early stage appears to be indication that the PLA as a whole was already starting to focus on advancing its UAV capabilities through more systematic training at that time. Since PLA updated most of its OMTE in 2009, this UAV OMTE may have been revised at that time or remain pending revision.

Li Chanyong, the "UAV King"

Despite the efforts to advance education and training, certain shortcomings have remained and could persist, despite at least ad hoc efforts to mitigate them. According to Major Li Changyong (æ?é?¿å??), the commander of a PLA Army UAV battalion, “that the UAV specialization has gaps isn’t frightful, perhaps it’s that everyone is waiting for someone else to come fill in the gaps.”[22] As of the mid-2000s, due to the lack of sufficiently standardized operations regulations, instruction regarding UAVs was often “reliant on a single person’s experience.”[23] As such, when he took on the post of UAV battalion commander in 2012, Li Changyong, characterized in PLA media as the “UAV king” (æ? ?æ?ºç??), took the initiative to compile lengthy regulations regarding the operation of the UAV model with which his unit was equipped, based on extensive engagement with local UAV manufacturers and technicians.[24,25] As of 2016, Li’s UAV battalion had also introduced its own simulation training room within which UAV operators could practice.[26] It is unclear how extensively such new regulations and successful practices for training have been implemented across the PLA to date.[27] There also appears to have been active experimentation at the unit level with new tactical approaches for the use of UAVs.[28,29] However, in some cases, the frequency of PLA training with UAVs may be restricted by considerations of airspace and aviation management, perhaps in competition with manned aircraft.[30]

Ju Xiaochengm the UAV "Golden Launcher"

The PLA’s apparent attention to personnel and training for unmanned operations is vividly reflected in the high-profile recognition of UAV operators and their importance. When Xi Jinping met the PLA’s delegation to the National People’s Congress in March 2016, one of the military personnel whom received particular notice was Master Sergeant Class One (ä¸??å???é?¿) Ju Xiaocheng (??æ?), the director of an unmanned aerial vehicle (UAV) launch site subordinate to the Army Artillery Academy. Based on his record of 100% accuracy in UAV launches, he has been praised as the PLA’s “golden launcher” (“é??ç??å?å°?æ??”) of military-use UAVs.[31] Among the PLA’s first UAV specialty non-commissioned officers (æ? ?æ?ºä¸?ä¸??å®?), Ju Xiaocheng was responsible for operating and maintaining UAVs, while training an estimated 80% of the entire PLA’s UAV specialty cadre (æ? ?æ?ºä¸?ä¸??é?¨), which includes UAV operators (æ?ä½?æ??) and technicians (æ??å¸?).[32,33] At the time, Xi Jinping declared to Ju Xiaocheng, “UAVs are important combat forces for the modern battlefield. You must carry out your duties well and cultivate good personnel.”[34] Indeed, the UAV specialty has been characterized as an urgently needed discipline for the PLA, in which enrollment is targeted to continue to increase.[35] Since the PLA is building up its cadre of UAV operators in peacetime, without the pressures associated with meeting the demands of ongoing combat operations, it has perhaps thus far avoided certain challenges of recruitment and retention that the U.S. military has faced.

The PLA’s approach to employment of unmanned systems and requirements for their operators differ across services. The PLA Army primarily operates smaller, tactical UAVs such as the ASN-206 and ASN-207, used for battlefield reconnaissance and electronic warfare. The PLA Rocket Force similarly appears to use UAVs primarily for such roles as battle damage assessment and perhaps guidance for long-range missiles. The PLA Navy and Air Force, on the other hand, also operate larger and more sophisticated UAVs, the medium-altitude long-endurance (MALE) BZK-005, used for reconnaissance, and the GJ-1 (Gongji-1, æ?»å?»-1,) variant of the Pterodactyl (Yilong, ?é¾? or Wing Loong), a MALE UAV used for integrated reconnaissance and strike. The PLA has been testing and may soon field the GJ-2, a more advanced version of the Pterodactyl.[36,37] The ongoing and future introduction of new types of UAVs, ranging from the ASN-301, a reversed-engineered version of Israel’s Harpy, an anti-radiation drone, to the Xianglong (“Soar Dragon,” ç¿?é¾?), a high-altitude long-endurance (HALE) UAV for potential missions of long-range reconnaissance and electronic warfare, could also create new challenges for operators.[38-41]

Li Hao, His Colleagues, and the GJ-1

In particular, within the PLA Air Force, a number of UAV pilots have transitioned from careers as pilots of manned aircraft to UAVs as this service has actively built up its unmanned combat forces. For instance, Li Hao (æ??), a UAV pilot prominently profiled in PLA media, decided to take on that role in 2010 once he could no longer continue as a traditional pilot.[42] In his career as a UAV pilot, Li Hao has taken on a key role in the construction the PLA Air Force’s UAV capabilities, actively contributing to breakthroughs in technical and operational challenges to increase combat effectiveness. As portrayed in media accounts, Li Hao has expressed great enthusiasm for “the golden combination of new-type unmanned warfare forces and new manned aircraft technology and tactics,” reflecting the PLA’s focus on techniques parallel to the U.S. military’s manned-unmanned teaming.[43] He has taken the lead in the initial incorporation of UAVs into Air Force operations, first in the 2012 Red Sword (?å??) exercise, in which UAVs were used for reconnaissance and imagery, and then again piloted the GJ-1 in its first engagement in a live-fire strike in a joint, PLA-wide exercise in 2014 and then its participation in Peace Mission 2014, a counterterrorism exercise with the Shanghai Cooperation Organization.[44] Li Hao also played an integral role in helping the PLA adjust to the personnel challenges associated with the operation of more complex UAVs, seeking to mitigate the lack of standardized training materials and accelerate the cultivation of talent, including through writing “UAV Training Requirements” (æ? ?æ?º?ç»???).[45] For the PLA Air Force, key and continuing challenges include operating under complex electromagnetic environments and enhancing coordination between manned and unmanned systems.

Li Hao

Looking beyond the increasing sophistication of China’s unmanned systems, the PLA’s actual operational UAV capability will depend upon these human and organizational dimensions of its approach to these systems. It is notable that the PLA appears to have progressed substantively in its institutionalization of education and training programs, as well as a career track for UAV officer and enlisted force operators, across multiple services. There could be but are not obvious indications of cultural or organizational resistance to the PLA’s widespread adoption of UAVs, even though these uninhabited systems could, in some cases, displace conventional pilots and platforms. Frictions could be less prevalent because unmanned systems are considered among “new-type forces” (æ?°å??å??é?) of key strategic importance, and there have not been controversies akin to those that have arisen in the U.S. context due to the uses of unmanned systems for counterterrorism campaigns.[46]

Indeed, the PLA appears enthusiastic in its embrace of UAVs, seeking to capitalize upon the anticipated transformation of the character of conflict towards “unmanned, intangible, silent warfare” (“æ? ?, æ? ?, æ? ?”æ??äº?) that is increasingly “intelligentized” (æ?ºè?½å??) due to the advent of AI on the battlefield.[47] The PLA’s expanding employment of unmanned systems for multiple missions will likely result in the establishment of new dedicated UAV units, further increasing the demand for qualified UAV operators and technicians. Despite continued challenges, the PLA remains focused on enhancing its UAV forces’ operational capabilities, while engaging in more sophisticated joint training exercises with unmanned systems, including in major exercises like “Firepower” (Huoli, ?å??) and Stride (Kuayue, ?è¶?).

What does the PLA’s approach so far to the humans behind their unmanned systems reveal about its potential engagement with the challenges associated with the highly automated and autonomous systems it is currently developing? Despite the myth that such systems tend to replace humans, requiring smaller numbers of combatants with lower levels of expertise, there is clear evidence to date that the human challenges of such systems are considerable, often requiring higher levels of specialized training.[48] In this regard, PLA’s active focus on the development of personnel to operate UAVs could constitute an early case that demonstrates that the PLA will likely confront considerable challenges in the process of learning to use such high-tech systems more effectively, given that human capital and training have remained major issues. However, it appears that the PLA does recognize the importance of the human element in the machine age of warfare.

Although the PLA seems to have less of an aversion than the U.S. military to taking humans out of the loop in operational circumstances in which doing so may be advantageous, there are indications that it is nonetheless focused on the value of human-machine collaboration and integration. For instance, it is telling that PLA theorists are starting to incorporate the distinction between humans in the loop and on the loop (i.e., exercising supervisory control) into their writings, and even into a patent for a system designed to allow a human operator to control multiple UAVs.[49,50] Lieutenant General Liu Guozhi, head of the Central Military Commission’s Science and Technology Commission, anticipates that human-machine hybrid (?æ?º?å?) intelligence will be the highest form of future intelligence.[51] As warfare progresses towards the machine age, the PLA and U.S. military alike will confront new challenges at this intersection of humans and new technologies.

Elsa B. Kania is an Adjunct Fellow with the Technology and National Security Program at the Center for a New American Security, where she focuses on Chinese defense innovation and emerging technologies. She is the author of “Battlefield Singularity: Artificial Intelligence, Military Revolution, and China’s Future Military Power.”

This article appeared originally at Strategy Bridge.

[1] Thank you to Paul Scharre for highlighting the importance of this distinction between “unmanned” and “uninhabited.”

[2] Robert R. Hoffman, Timothy M. Cullen, and John K. Hawley, “The myths and costs of autonomous weapon systems,” Bulletin of the Atomic Scientists, July 3, 2016, https://thebulletin.org/2016/july/myths-and-costs-autonomous-weapon-systems9635

[3] There has been recurrent media coverage of these challenges. See, for instance: “Air Force Will Offer Bonuses To Lure Drone Pilots,” Wall Street Journal, July 14, 2015, https://www.wsj.com/articles/air-force-will-offer-bonuses-to-lure-drone-pilots-1436922312

[4] “Chairman Xi Met with Some Grassroots Cadres and Educational and Scientific Front Line Military Representatives to the National People’s Congress” [???æ?¥?é?¨å??å?ºå±?é?¨é??å??æ???ç§?ç ?ä¸??å??é??????], China Military Online, March 14, 2016, http://jz.chinamil.com.cn/n2014/tp/content_6959465.htm.

[5] This article is informed by an initial piece written in collaboration with Ken Allen, and thank you, as always, to Ken for reminding me to focus on the human side of the PLA. See:  Elsa Kania and Kenneth Allen, “The Human and Organizational Dimensions of the PLA’s Unmanned Aerial Vehicle Systems,” China Brief, May 11, 2016, https://jamestown.org/program/the-human-and-organizational-dimensions-of-the-plas-unmanned-aerial-vehicle-systems/

[6] “The Explosive Development of China’s UAVs” [?å?½æ? ?æ?ºäº?å?·å?å±?], China Youth Daily, January 23, 2015, http://mil.huanqiu.com/observation/2015-01/5481399.html. “A Fighter Jet Outwits a UAV” [æ??æ??æ?ºæ??æ³?æ? ?æ?º], People’s Daily, March 18, 2003, http://www.people.com.cn/GB/junshi/192/3615/5679/20030318/946058.html

[7] Prior to the Sino-Soviet Split, Sino-Russian defense cooperation incorporated weapons sales. For more historical context, see, for instance: Lorenz M. Lüthi, The Sino-Soviet Split, Princeton University Press, 2008.

[8] “The Explosive Development of China’s UAVs” [?å?½æ? ?æ?ºäº?å?·å?å±?], China Youth Daily, January 23, 2015, http://mil.huanqiu.com/observation/2015-01/5481399.html

[9] Ibid.

[10] See, for instance: Kimberly Hsu, Craig Murray, Jeremy Cook, and Amalia Feld, “China’s Military Unmanned Aerial Vehicle Industry,” US-China Economic and Security Review Commission, 2013.

[11] “The Explosive Development of China’s UAVs” [?å?½æ? ?æ?ºäº?å?·å?å±?],

[12] “China’s Father of UAVs” [?å?½æ? ?æ?ºä¹?ç?¶”é????], China Air Force, October 8, 2013, http://kj.81.cn/content/2013-10/08/content_5692763.htm

[13] For more context on drone proliferation, see: Elisa Catalano Ewers, Lauren Fish, Michael C. Horowitz, Alexandra Sander, and Paul Scharre, “Drone Proliferation: Policy Choices for the Trump Administration,” June 2017, http://drones.cnas.org/wp-content/uploads/2017/06/CNASReport-DroneProliferation-Final.pdf.

[14] “PLA NCO Taught 80% of the Whole Military’s UAV Specialty Cadre” [?æ?¾å???å®??å?¨å??80%æ? ?æ?ºä¸?ä¸??é?¨æ??è¿??], Xinhua, May 26, 2009, http://mil.news.sina.com.cn/2009-05-26/1328552994.html

[15] The full list is available upon request. Since the PLA has been restructuring its military educational institutions pursuant to the ongoing reforms, there may be changes to existing educational programming in this domain.

[16] “The Chinese People’s Liberation Army’s Naval Aviation Engineering Academy Undergraduate Specialties” [?å?½?æ°??æ?¾å???å??è?ª??ç¨??é?¢æ?¬ç§?ä¸?ä¸?], June 27, 2014, http://www.gk169.com/news90094/ 

[17] “Information on Ordnance College’s “Real Explosion, Real Fly” Exercises” [å????é?¢“å®?ç??ã?å®?é£?”æ¼?ç»??é?»], China Army Network, May 5, 2015, http://army.81.cn/content/2016-05/05/content_7036848.htm

[18] See, for instance: “Guangzhou Military Region Explores Multiple Models of UAVs’ Cooperative Operations Under Informatized Conditions” [?å·?å??å?ºå¤?å??æ? ?æ?º?å? æ?¢???å????ä¸?ä½?æ??], PLA Daily, April 13, 2015, http://mil.huanqiu.com/china/2015-04/6168892.html

[19] “Military-Use UAV “Golden Launcher” Ju Xiaocheng” [å??ç?¨æ? ?æ?º"é??ç??å?å°?æ??"??æ?].

[20] OMTE might be characterized as roughly equivalent to the U.S. Marine Corps Training and Readiness Manual. Thanks to Olivia Garard for raising this analogy. See: http://www.marines.mil/Portals/59/Publications/NAVMC%203500.44C%20Infantry%20T-R%20Manual%20(secured).pdf?ver=2017-03-09-080222-740

[21] Thanks to Ken Allen for his explanation of OMTE.

[22] “PLA New-Type UAV Fielded in the Direction of the East (China) Sea” [?æ?¾å??æ?°å??æ? ?æ?ºé?¨?ä¸??æ?¹å?], China Military Online, August 15, 2014, http://news.qq.com/a/20140815/030417.htm

[23] Ibid.

[24] “PLA New-Type UAV Fielded in the Direction of the East (China) Sea” [?æ?¾å??æ?°å??æ? ?æ?ºé?¨?ä¸??æ?¹å?],

[25] “Our Military First Group of UAV Specialty Graduates Li Changyong, Five Records Achieved” [æ??å??é¦?æ?¹æ? ?æ?ºä¸?ä¸?æ¯?ä¸?ç??æ?é?¿å?? 5å???å½?], PLA Daily, August 10, 2014, http://www.81.cn/lj/2014-08/10/content_6086790.htm

[26] “A Million Units of UAV Real Flying, Data Loaded Onto a Simulation Training System” [ä¸?ç»?æ? ?æ?ºå®?é£?æ?°?è£?å?¥?æ???ç»??ç»?], PLA Daily, March 2, 2016, http://news.xinhuanet.com/mil/2016-03/02/c_128767751.htm

[27] There have been multiple narratives in PLA media of similar cases in which “gaps” had to be filled through the initiative of a single unit or commander, particularly for PLA Army UAV units. Similar anecdotes include that of a UAV battalion within the 1st Group Army (PLA Daily, March 3, 2015), and a UAV team within the 47th Group Army (PLA Daily, March 31, 2016). In each case, the unit or commander in question realized that there were certain “blanks” or “gaps” in existing training materials and took the initiative to develop their own.

[28] “Battalion Commander Li Changyong Created the Whole Military’s First Five-Part UAV Flight” [?é?¿æ?é?¿å??ï¼?å??é? æ? ?æ?ºé£?è¡?5?å?¨å???ä¸?], PLA Daily, August 15, 2014, http://www.81.cn/jwgz/2014-08/15/content_6095338_3.htm

[29] “Our Military’s First Group of UAV Specialty Graduates Li Changyong Achieved Five Records” [æ??å??é¦?æ?¹æ? ?æ?ºä¸?ä¸?æ¯?ä¸?ç??æ?é?¿å?? 5å???å½?].

[30] “The UAV Lacks a Rival to Confirm its Efficacy, Why Not Seek Out the Missile Battalion Next Door To Try” [æ? ?æ?º?æ???æ????æ??æ??ï¼?ä½??æ?¾é??????è¯?], PLA Daily, May 4, 2016, http://www.81.cn/jwzl/2016-05/04/content_7037314.htm

[31] “Chairman Xi Met with Some Grassroots Cadres and Educational and Scientific Front Line Military Representatives to the National People’s Congress” [???æ?¥?é?¨å??å?ºå±?é?¨é??å??æ???ç§?ç ?ä¸??å??é??????], China Military Online, March 14, 2016, http://jz.chinamil.com.cn/n2014/tp/content_6959465.htm.

[32] “Military-Use UAV “Golden Launcher” Ju Xiaocheng [å??ç?¨æ? ?æ?º"é??ç??å?å°?æ??"??æ?], China Military Online, March 15, 2016, http://jz.chinamil.com.cn/zhuanti/content/2016-03/15/content_6961282.htm

[33] “PLA NCO Taught 80% of the Whole Military’s UAV Specialty Cadre” [?æ?¾å???å®??å?¨å??80%æ? ?æ?ºä¸?ä¸??é?¨æ??è¿??].

[34] “Chairman Xi Met with Some Grassroots Cadres and Educational and Scientific Front Line Military Representatives to the National People’s Congress” [???æ?¥?é?¨å??å?ºå±?é?¨é??å??æ???ç§?ç ?ä¸??å??é??????].

[35] For instance: “2016 Military Academies Recruitment, which specialties expanded recruitment, which institutions?” [2016å???æ??ç??ï¼?å?ªäº?ä¸?ä¸?æ?©æ??ï¼?é?¢?æ??å?ªäº?ï¼?], Xinhua, April 27, 2016, http://news.xinhuanet.com/mil/2016-04/27/c_128937528.htm

[36] “AVIC unveils Wing Loong II armed reconnaissance UAV,” IHS Jane’s International Defense Review, November 7, 2016, http://www.janes.com/article/65322/avic-unveils-wing-loong-ii-armed-reconnaissance-uav.

[37] “Deciphering the World Class Pterodactyl UAV” [??ä¸?ç??ä¸??ç??“?é¾?”æ? ?æ?º], Xinhua, December 9, 2016, http://news.xinhuanet.com/mrdx/2016-12/09/c_135892371.htm

[38] Dennis J. Blasko, Elsa Kania, and Stephen Armitage, “The PLA at 90: On the Road to Becoming a World-Class Military?,” China Brief, August 17, 2017, https://jamestown.org/program/the-pla-at-90-on-the-road-to-becoming-a-world-class-military/

[39] Andrew Tate, “China’s Xianglong HALE UAV to enter service shortly, says report,” IHS Jane's Defence Weekly, December 21, 2016, http://www.janes.com/article/66431/china-s-xianglong-hale-uav-to-enter-service-shortly-says-report

[40] “New drone to beef up PLA aerial skills,” China Daily, December 7, 2016, http://www.china.org.cn/china/2016-12/07/content_39866858.htm

[41] For an overview of Chinese advances in and missions for unmanned systems, see the author’s  testimony to the U.S.-China Economic and Security Review Commission on the topic. Elsa B. Kania, “Chinese Advances in Unmanned Systems and the Military Applications of Artificial Intelligence—the PLA’s Trajectory towards Unmanned, “Intelligentized” Warfare,” Testimony before the U.S.-China Economic and Security Review Commission, February 23, 2017, https://www.uscc.gov/Hearings/hearing-china%E2%80%99s-advanced-weapons-video

[42] “UAV Pilot Li Hao” [æ? ?æ?ºé£?è¡?å??æ??], PLA Daily, December 11, 2015, http://www.81.cn/jwgz/2015-12/11/content_6811924.htm

[43] “The Air Force’s First-Group UAV Pilot, Li Hao” [?å??é¦?æ?¹æ? ?æ?ºé£?è¡?å??æ??], People’s Daily, May 23, 2017, http://military.people.com.cn/n1/2017/0523/c1011-29295213.html

[44] Ibid.

[45] “The Air Force’s First-Group UAV Pilot, Li Hao: A New Road to Exploring Talent Cultivation” [?å??é¦?æ?¹æ? ?æ?ºé£?è¡?å??æ??ï¼?æ?¢??æ?å?¹å?»æ?°??], May 28, 2017, http://military.cnr.cn/ztch/kjlh/jjlh/20170528/t20170528_523776728.html

[46] Although the use of unmanned systems has remained popular with the American public, global public opinion has reflected widespread opposition to U.S. drone strikes. See, for instance: Jacquelyn Schneider and Julia Macdonald, “U.S. Public Support for Drone Strikes,” Center for a New American Security, September 20, 2016, https://www.cnas.org/publications/reports/u-s-public-support-for-drone-strikes and “Global Opposition to U.S. Surveillance and Drones, but Limited Harm to America’s Image,” Pew Research Center, July 14, 2014, http://www.pewglobal.org/2014/07/14/global-opposition-to-u-s-surveillance-and-drones-but-limited-harm-to-americas-image/

[47] Academy of Military Science Military Strategy Research Department [å??äº?ç§??é?¢å??äº?æ??ç?¥ç ??é?¨], The Science of Military Strategy [æ??ç?¥?], Military Science Press [å??äº?ç§??å?ºç???], 2013, 97-98.

[48] Robert R. Hoffman, Timothy M. Cullen, and John K. Hawley, “The myths and costs of autonomous weapon systems,” Bulletin of the Atomic Scientists, July 3, 2016, https://thebulletin.org/2016/july/myths-and-costs-autonomous-weapon-systems9635

[49] Zhu Huayong [æ?±å?å??], Niu Yifeng [ç????], Shen Lincheng [æ²?æ??æ?], and Zhang Guozhong [?å?½?], “Current Situation and Development Trend of Autonomous Control Technologies for UAV System” [æ? ?æ?º?ç»?è?ª?æ?§å?¶æ??æ?¯ç ??ç?°ç?¶ä¸?å?å±?è¶?å?¿], Journal of National University of Defense Technology [å?½é?²ç§?æ?????æ?¥], 32, no. 3 (2010):

[50] Niu Yifeng [ç????] et al., “Hybrid Active Control Method for Single Operator Multiple UAVs Based on Multi-Modal Natural Interactions” [å?ºäº?å¤??æ?è?ªç?¶?äº?ç??å?æ?ä½?å??å¤?æ? ?æ?º?å??å?¨æ?§å?¶æ?¹æ³?], National University of Defense Technology, September 21, 2016. 

[51] “National People’s Congress Representative Liu Guozhi: Artificial Intelligence Will Accelerate the Process of Military Transformation” [????å??å?½?ï¼???æ?ºè?½å°?å? é??å??äº?å??è¿?ç¨?].