题目: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
答案:评论后可见此内容
推荐使用我们的公众号搜索题目,题目更全,检索更方便。支持语音、图片、文字等多种搜索方式。