Question

Loulan is believed __________ over by sandstorms gradually from AD200 to AD400.

A．to cover	B．to be covered
C．to have covered	D．to have been covered

Answer 1

D

試題分析：考查句型：sb/sth is believed to do/to have done,據(jù)相信某人/某物…，如果是將要做，用不定式一般式to do如果是已經(jīng)做了，用不定式的完成式，句意：大家相信樓蘭是從公元前200年到公元前400年逐漸被沙塵暴淹沒的。因為樓蘭是被掩埋的，用不定式完成式的被動，選D。
點評：固定句型是學(xué)習(xí)語言的重要環(huán)節(jié)。sb/sth is reported /believed to do/to have done,可以轉(zhuǎn)化成It is reported /believed that句型，解答這類題目，關(guān)鍵是理解題干意思從而判斷是動詞不定式的什么形式，根據(jù)意思放入句子中進行比較，不難選出正確答案。