![](http://www.ecns.cn/hd/2020/04/10/8f3ae23aa9b14a3b9cf791efaca2ccfe.jpg)
A medical worker at a COVID-19 drive-thru testing site uses a swab to take a sample at the George Washington University Hospital in Washington D.C., the United States, on April 9, 2020. (Photo by Ting Shen/Xinhua)
![](http://www.ecns.cn/hd/2020/04/10/cd27edab4d4348568426e2381593cd88.jpg)
A medical worker at a COVID-19 drive-thru testing site uses a swab to take a sample at the George Washington University Hospital in Washington D.C., the United States, on April 9, 2020. (Photo by Ting Shen/Xinhua)
![](http://www.ecns.cn/hd/2020/04/10/acb80053e612456e9fce99f78b74737d.jpg)
Photo taken on April 9, 2020 shows a COVID-19 drive-thru testing site at the George Washington University Hospital in Washington D.C., the United States. (Photo by Ting Shen/Xinhua)
![](http://www.ecns.cn/hd/2020/04/10/1b9700faa25c4f51a479226ca285221a.jpg)
A medical worker at a COVID-19 drive-thru testing site uses a swab to take a sample at the George Washington University Hospital in Washington D.C., the United States, on April 9, 2020. (Photo by Ting Shen/Xinhua)
![](http://www.ecns.cn/hd/2020/04/10/8d8d5544989443838c1f1b79afe26ab0.jpg)
Medical workers at a drive-thru testing site prepare for the COVID-19 test at the George Washington University Hospital in Washington D.C., the United States, on April 9, 2020. (Photo by Ting Shen/Xinhua)
![](http://www.ecns.cn/hd/2020/04/10/053efac85ab04e49a9dfdfa2f9fec45b.jpg)
A staff member directs cars to a COVID-19 drive-thru testing site at the George Washington University Hospital in Washington D.C., the United States, on April 9, 2020. (Photo by Ting Shen/Xinhua)