问题
单项选择题
When I talked with my grandma on the phone, she sounded weak, but by the time we ______ up, her voice had been full of life.
A. were hanging
B. had hung
C. hung
D. would hang
答案
参考答案：C
解析： 考查动词时态。本句的意思是“当我与祖母在电话上交谈时，她的声音听起来有气无力，但要挂电话时，她的声音却充满了活力。”此处是陈述一个事实，且为过去发生的动作，故应用一般过去式。答案是C项。