问题
选择题
Every few years, the coal workers ________ their lungs Xrayed to ensure their health.[ ]
A. are having
B. have
C. have had
D. had had
答案
答案:B
Every few years, the coal workers ________ their lungs Xrayed to ensure their health.[ ]
A. are having
B. have
C. have had
D. had had
答案:B