As is natural, a man as old as he ______ be very forgetful.A．canB．mustC．shouldD．

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As is natural, a man as old as he ______ be very forgetful.

A．can

B．must

C．should

D．would

答案

解析

can通常用来表示“理论上的可能性”，并不涉及到是否真的会发生，本句中即是此意，“从自然规律上来讲，象他这样的老人会很健忘”。

举一反三

—The poor people lived near the highway.

—_____ very noisy.

A．It must have been

B．They must be

C．That might be

D．There must be

题型：不详难度：| 查看答案

He _____ his parents that he has failed in the exam.

A．dares not tell

B．dares not telling

C．dare not tell

D．dares not to tell

题型：不详难度：| 查看答案

Messages ______ be changed from sound into electricity before they ______ be sent by radio.

A．must; will

B．have to; can

C．can; must

D．need; may

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The whole building _____ burned down, but the heavy rain _____.

A．might have; would help	B．could have been; helped	C．must have; helped
D．should have been; was helping

题型：不详难度：| 查看答案

—Many people in England love to give advice on weather reporting.

—Yes, but I think the weather office’s computers _____ be more accurate.

A．can

B．must

C．ought to

D．might

题型：不详难度：| 查看答案