Scientists say it may be five or six years _____ this medicine is tested on huma

游客2024-01-14  18

问题 Scientists say it may be five or six years _____ this medicine is tested on human beings.

选项 A、since
B、before
C、after
D、when

答案 B

解析
转载请注明原文地址:https://www.tihaiku.com/zcyy/3362619.html
最新回复(0)