Question

【题目】Now all passengers show their ID cards and go through the safety check before they take a train.

A.would B．may C．could D．must

Answer 1

【答案】D

【解析】

试题分析：句意：现在所有的乘客必须出示身份证并通过安检，才能上火车。A.would愿，要；B．may可以；C．could可以，表示许可；可能，表示肯定的推测；D．must必须。旅客必须出示身份证并通过安检才能上火车，必须：must。故选D。