Question

【题目】Some aspects of a pilot’s job ___ be boring, and pilots often ___work at inconvenient hours.

A. can; have to

B. may; can

C. have to; may

D. ought to; must

Answer 1

【答案】A

【解析】前面考查情态动词can的推测用法，表示理论上的可能性；后面考查情态动词have to的本义，表示客观事实的限制。