单选题
—I was told that Jack had a car accident yesterday. —I believe not. He______. A. shouldn't have been so careless B. wouldn't be so careless C. couldn't be so careless D. mustn't be so careless
【正确答案】
C
【答案解析】[解析] 这是一组情态动词的特殊用法，它们的意义分别为：couldn’t have done：表示一种推测：不可能做，含有主观因素；shouldn't have done：(过去)不应该做；wouldn't have done：用于虚拟语气中，表示与过去事实相反的结果。mustn't do：表示现在绝对不能做。