Without the help of people from every corner of the world, people in Wenchuan County, Sichuan Province__________recovered very quickly from the May Twelfth Earthquake.
A、must not have
B、couldn't have
C、may not have
D、can't have
【正确答案】：B
【题目解析】：考查虚拟语气。句意为:“如果没有各国的援助，四川汶川的人们不可能很快从5·12大地震中恢复过来。”couldn’t have done意为“不可能做某事”。
