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
网友回答
A. are having
(答案→)B. have
C. have had
D. had had
解析：本题考查时态。根据时间状语every few years,可判断本句应为一般现在时，因此答案选B。句意：每过几年，煤矿工人都要做X射线保证他们的健康。