If you're going to come,please let me know _______.before Bin ahead Cin advance
问题描述：
If you're going to come,please let me know _______.before Bin ahead Cin advance
If you're going to come,please let me know _______.before
Bin ahead
Cin advance
答
选C in advance 提前（指时间）,而A项before在.之前,一般后面有具体的时间,B项in ahead之前（指位置）