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。