When I talked with my grandma on the phone,she sounded weak,bu by the time we____up,her voice had be

题目

When I talked with my grandma on the phone,she sounded weak,bu by the time we____up,her voice had been full of life.
A.were hanging B.had hung C.hung D.would hang
另外这个题目的意思我不太懂

答案

by the time 是一个明显的完成时标志,看到它主句用完成时,从句用过去时~记下来就好了,hung 是hang的过去式.这就话就是说,当我与奶奶在电话中交谈时,她声音很虚弱,但当我要挂电话时,她声音充满了活力.