Scientists say that the Mars-500 days_______they perform the task_英语解答

Scientists say that the Mars-500 days_______
they perform the task during the real mission
-Good luck.I hope it goes well.
A. after B. before C. sinceD. as
请问为什么?另外,这句话怎么翻译?

人气：386 ℃　时间：2020-01-31 08:15:12

解答

Scientists say that the Mars-500 days___B____they perform the task during the real mission
-Good luck.I hope it goes well.
A.after B.before C.since D.as