Alice _____ ill, for she didn.t come to the class yesterday. A.was B.had been C.must have been D.should have been
答案是:参考答案:C 答案解析: for前多加逗号,一般是对结果作出推断性的补充说明或解释,不表示直接原因,这里用must have done意为“一定是做了某事”,用should have done意为“过去本应该做某事,而实际未做”,所以这里应该是猜测Alice一定是病了,因为她昨天没有来上学,故选择C。