Self check 

【参考答案】

Self check 1 部分Complete the passage with the correct forms of the words in the box.

用方框中单词的适当形式完成短文。

invent发明

doubt怀疑

mention提到

nearly几乎

website网站

all of a sudden突然

It is often difficult to decide on the inventor of certain inventions. This is because sometimes a few people may invent things which are nearly the same. It's hard to tell who came up with the idea first. Some inventions can also lead to other inventions all of a sudden. So some people doubt whether the inventor came up with the idea himself or herself. They think that the inventor used someone else's idea to create his or her invention That is why books or websites usually mentionmore than one inventor when giving information about inventions.

通常很难判断具体发明的发明者。这是因为有时候一些人可能发明几乎相同的东西。很难说谁是第一个提出想法的人。有些发明也能突然导致其他的发明。因此一些人怀疑是否是发明者他或她自己提出的想法。他们认为发明者用别人的想法创造了他或她的发明。那就是为什么书本或网站在给出有关发明信息的时候通常提到不止一位发明者。

Self check 2 Rewrite these sentences using the passive voice.

用被动语态重写这些句子。

1. Someone stole my watch.

1．有人偷了我的手表。

2. They used five eggs to make this big cake.

2．他们用五个鸡蛋做的这个大蛋糕。

3. When did they invent the personal computer?

3．他们什么时候发明的个人电脑？

4. They asked us not to run in the hallway.

4．他们让我们不要在走廊里跑。

5. Someone took the video back to the store.

5．有人把录像带带回商店。

【参考答案】

【解析】

(1)My watch was stolen by someone .

(2)Five eggs were used to make this big cake by them .

(3)When was the personal computer invented by them ?

(4)We were asked not to run in the hallway by them .

(5)The video was taken back to the store by someone .