题干
Hello, I____ you____ in London. How long have you been here?
A：don’t know; were
B：hadn’t known; are
C：haven’t known; are
D：didn’t know; were
答案(点此获取答案解析）
D
A：don’t know; were
B：hadn’t known; are
C：haven’t known; are
D：didn’t know; were
为△
内一点，若任意
，有
，则△