Up till then we () half the destance.

问题描述:

Up till then we () half the destance.
A.had only covered
B.covered
C.would only cover
D.would be only covered

A请问为什么选A呢?是倒装么?不是倒装,up till then 应该是和过去完成时连用,up to now 和现在完成时连用