Every few years, the coal workers ___________ their lungs X-rayed to ensure their health.A．are havin

题目简介

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

题型：单选题难度：偏易来源：不详

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。