【题目】He ________ without saying goodbye to them, for he always has good manners.
A. can’t have left B. may not have left
C. shouldn’t have left D. mustn’t have left
在线课程【答案】A
【解析】
试题分析： A考查情态动词表猜测，解本题一定要注意审题，要把题目看完整，才不会想当然选C，根据后文的for he always has good manners可以断定“他不可能不打招呼就离开”，用can’t have left，所以答案是A。