问题补充：
---Where were you when I called at your house this morning?
---Oh, I for a friend from Tokyo at the airport．
A. had waited
B. am waiting
C. have waited
D. was waiting
答案：
A. had waited
B. am waiting
C. have waited
(答案→)D. was waiting
解析：可联系答.案.网客服索取。
