据利物浦热带医学院的彼得·桑迪福德说，没有人确切地知道。

According to Peter Sandiford of the Liverpool School of Tropical Medicine, no one knows for certain.

youdao

据利物浦热带医学院的彼得·桑迪福德说，没有人确切地知道。

According to Peter Sandiford of the Liverpool School of Tropical Medicine, no one knows for certain.

youdao