1.-I'm sorry to have kept you waiting so long.

1.-I'm sorry to have kept you waiting so long.
-Never mind.I_________here for only a few minutes.
A.have been B.have come C.have arrived D.was coming
2.-Excuse me,could you tell me__________?
-Sorry,sir.I wasn't there at that time.
A.how did the accident happen
B.how the accident happened
C.how does the accident heppen
D.how the accident happens
同求原因,特别是第二题QAQ