When astronauts return to the earth’s atmosphere, helicopters fly to they would land, ready to collect them.
A. what
B. where
C. which
D. that
网友回答
A. what
(答案→)B. where
C. which
D. that
解析：本题考查名词性从句。句中where引导宾语从句，在从句中作地点状语。句意：当宇航员返回到地球大气层的时候，直升机飞往他们将降落的地方，准备运走他们。