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
网友回答
A. were hanging
B. had hung
(答案→)C. hung
D. would hang
解析：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。