Hi,Mike!Nice to meet you here.I _____ you joined the club.A.didn't know.B.haven't known.
问题描述:
Hi,Mike!Nice to meet you here.I _____ you joined the club.A.didn't know.B.haven't known.
为什么
答
选择A.didn't know.,因为你现在已经知道了,所以不能用完成时