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

admin2019-07-18  59

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://jikaoti.com/ti/DpDYFFFM
0

最新回复(0)