![Photo shows newly arrived giant panda Yuan Yuan sitting in his enclosure at the Schonbrunn Zoo in Vienna, Austria on Wednesday, April 17, 2019. The 20-year-old male panda left China for Austria on Tuesday for a four-year collaborative research project. (Photo/Agencies)](http://www.ecns.cn/hd/2019/04/18/3d9abd2b67ff48a39d194c95561543ca.jpg)
Photo shows newly arrived giant panda Yuan Yuan sitting in his enclosure at the Schonbrunn Zoo in Vienna, Austria on Wednesday, April 17, 2019. The 20-year-old male panda left China for Austria on Tuesday for a four-year collaborative research project. (Photo/Agencies)
![Photo shows newly arrived male panda Yuan Yuan walking in his enclosure at the Schonbrunn Zoo in Vienna, Austria on Wednesday, April 17, 2019. (Photo/Agencies)](http://www.ecns.cn/hd/2019/04/18/60c5c7edaef344d6a4aee85a741b6b80.jpg)
Photo shows newly arrived male panda Yuan Yuan walking in his enclosure at the Schonbrunn Zoo in Vienna, Austria on Wednesday, April 17, 2019. (Photo/Agencies)