533.Did you find the missing couple in the mountain yesterday?
No，but we ______ to get in touch with them ever since.
A.have tried
B.have been trying
C.had tried
D.had been trying
534.Got your driving license?
No.I _______ too busy to have enough practice,so I didn't take the driving test last week.
A.was
B.am
C.have been
D.had been
533.答案是B;ever since与现在完成时连用，但由于还没找到，所以仍在找。
534.答案是D;此处忙碌应发生在考驾照之前。
