问题
选择题
When I talked with my grandma on the phone, she sounded weak, but by the time we ____ up, he voice had been full of life．
A．were hanging
B．had hung
C．hung
D．would hang
答案
C
考查动词时态。此处是陈述一个事实，且为过去发生的动作，故应用一般过去时。