---How long is it we last met?
--- About five years. You haven’t changed much.
A. before
B. since
C. when
D. that
网友回答
A. before
(答案→)B. since
C. when
D. that
解析：连词辨析。Before在……之前；since自……以来；when当……时候；that，那个引导限制性定语从句。根据题意，根据下文，大约五年了，你没多大变化。可知上文要表达的意思是，自从我们上次见面有多久了？故选B。