26. It took us quite a long time to get to the amnuement park.It was __________ journey.
A. three hour B. a three-hours C. a three-hour D. three hours
27. If you parents do everything for us children ,we won’t learn to depend on ______.
A. themselves B. them C. have had D. ourselves
28. Every few years,the coal workers ___________ their lungs X-rayed to ensure their health.
A. are having B. have C. have had D. had had
29. –Sorry,Professor Smith. I didn’t finish the assignment yesterday.
-Oh, you ___________ have done it as yesterday was the deadline.
A. must B. mustn’t C. should D. shouldn’t