问题
选择题
They _____ have arrived at lunch time but the flight was delayed.
A．should
B．can
C．must
D．will
答案
答案：A
考察情态动词 should have done本应当干某事 can have done可能做了某事 must have done一定做了某事 will have done 将要做好
句意为，他们本应该在午饭的时候到达，但是航班被推迟了。