问题补充:
, we didn’t know each other, but now we are good friends.
A. First
B. First of all
C. At first
D. For the first time
答案:
A. First
B. First of all
(答案→)C. At first
D. For the first time
解析:A. First第一; B. First of all首先; C. At first 起先;D. For the first time第一次。结合下句但是现在我们是好朋友了可知上句是起先我们彼此不认识。故选C。