问题补充：
--- Mrs. Brown, I don’t think we can get there on time by bike.
--- You mean it’s for us to take a taxi?
A. necessary
B. important
C. possible
D. difficult
答案：
(答案→)A. necessary
B. important
C. possible
D. difficult
解析：本题考查的是it is +adj for sb to do sth，再根据意思可知答案为A
