-How amazing it is that astronauts are exploring outer space! -It’s a challenge, I guess,

发布时间：2020-08-15 00:40:02

-How amazing it is that astronauts are exploring outer space!  
-It’s a challenge, I guess,     man against nature.  
A. of
B. for
C. by
D. about

网友回答

(答案→)A. of
B. for
C. by
D. about
解析：应答句中的I guess是插入语，因此所填介词与challenge连用，表所属，用of，选A。
以上问题属网友观点，不代表本站立场，仅供参考！