Question

【题目】All passengers ________ go through safety check before they take a plane.

A. can B. may C. must D. ought

Answer 1

【答案】C

【解析】

试题分析：句意：所有乘客在乘飞机之前必须通过安检检查。A. can 能够； C. must D. ought

B. may可以；C. must必须；D. ought应该；根据句意此空应是必须的意思，所以应选C。