(2009北京30)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:C
解析:考查动词时态。hang up的动作应发生在 had been full of life之后,故应用一般过去时。
句意:当我和奶奶用电话交谈时,她的声音听起来很虚弱;但到我们挂电话时,她的声音已充满了活力。