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

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

根据句末的要求或提示改写下列句子

88. We can go to the museum today. We can also go there tomorrow. (用either…or…改写)

89. It is believed that Loulan was gradually covered by sandstorm from AD200 to AD400.（句式改写）

 Loulan is believed ____________________________________________________________ .

90. He didn’t go to bed until I came back. (对划线部分强调)

91.Luckily, we’d brought a road map. Without the road map we would have lost our way. (改为含有定语从句的复合句)

92. “Did you have an argument with Mary?” John asked.(改为间接引语)

93. Why does English have so many difficult rules that confuse people? That is the reason.(改为表语从句)

94. Nobody understood his speech，____________ ? (反意疑问句)

95. Their money was used up and they had to give up the project.(改成简单句)

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

1. A.
   to cover
2. B.
   to be covered
3. C.
   to have covered
4. D.
   to have been covered

Loulan is believed ____ by sandstorms from AD 200 to AD 400.