问题一：
--Could you show me the way to No.5 Middle School?
--I'm affraid I couldn't.I___never___there.
选项：A.do...go
B.did...go C.have...been D.had...been
问题二：
Mr.Black was surprised,"I___I lost my wallet."
选项：A.know B.don't know C.knew D.had seen
两题各选哪个答案？麻烦解释一下为什么选那个答案？感谢！
