二 情态动词：can和be able to 等
1．Can 和be able to
1）当指能力时，can和be able to可以互换，但be able to比can更加正式但也不常用。 如：My brother can/is able to play table tennis very well. 2) 我们用can来谈论将来可能发生的动作。
如：Let’s get some exercise. We can go and jog in the park.
3） be able to可以用在不同的时态中，可以后面直接接动词原形或放在另一个情态动词之
后。
如：I’m sorry I haven’t been able to play tennis with you recently. It’s nice to be able to attend the lecture.
Wang Gong might be able to win the chess game.
4) can的过去式是could，be able to的过去式是was /were able to 如：He could swim across the river when he was young.
Mike was a good swimmer, so he was able to take first place in the competition. 2 shall和 will
1）我们通常用shall来表达承诺，用will来表达决心或决定。 如：Don’t worry. You shall have the tickets for the games. Liu Mei will go and buy the tickets for the games.
2) 在疑问句中，shall用于第一人称或第三人称提供帮助或提建议，will用于第二人称和第三人称询问意愿。
如：Shall we go swimming this weekend?
A group of students are waiting to see you outside. Shall they come in?
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Will you go hiking with me in the mountain? Will he pay for me? 3 mustn’t和needn’t
Mustn’t用来表达让某人不做某事，needn’t用来表达做某事没必要。 如：You mustn’t miss this football match. It’s very important. You needn’t watch the game if you don’t want to. 4 need和dare
当用做情态动词时，这两个词常出现在否定句和疑问句中。这两个词还可以当做普通动词来用。
如：You needn’t / don’t need to go training if you feel tired. Dare he/ Does he dare to dive into the water from the bridge?
第三单元
一 被动语态
1．主动语态和被动语态在意思上没有太大区别，可以互换。在主动语态的句子中，我们用动作的发出者作为句子的主语；在被动语态的句子中，我们用动作的承受者作为句子的主语。 如：Scientists designed a VR headset. A VR headset was designed by scientists. 2 被动语态的基本结构是：be+-ed （动词的过去分词），在不同的时态中，be的形式是不一样的。例如，在一般现在时态中，be是is或are；在现在进行时态中，be是is/am/are+being；在现在完成时态中，be是have/has+been；在一般将来时态中，be是will+be。 如：Right now the new product is being developed in the laboratory.
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An agreement has been put forward. 3．当用被动语态的时候，以下几点需要注意：
1）我们通常用by来引导动作的发出者，但当没必要提及动作的发出者或动作的发出者不重要，或很难说出动作的发出者是谁时，动作的发出者可以省略不提。 如：he believes that VR films will be accepted by viewers.
Both the headsets and the gloves are connected to the RealCine computer system. 2） 动词give，lend，offer，send，tell和show后面可以接两个宾语，分别指人和物。当
这些
动词用做被动语态的时候，我们通常把动词后面接的人做为句子的主语；有些时候，也会把物作为主语。
如：They are offered headsets and gloves in the cinema. Headsets and gloves were offered to them in the cinema.
3）在主动语态中，一些动词后面往往接宾语和动词原形。在被动语态中，动词原形前面要接to。
如：I saw him go there. He was seen to go there.
4) 有时候，在被动语态中，get可以替换be。如：get changed, get dressed, get hurt 如：Please wait a while. I’ll just go and get changed. 4） 有些动词主动形式表被动含义。
如：This kind of computer sells well in China. Your article reads well. 5） 状态动词不能用于被动语态。 如：I have many science books.
VR films belong to the latest wave of new technology.
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4． 被动语态的其它特殊形式： 1） it+动词的被动语态+that从句
如：It is said that the technology behind RealCine is virtual reality. 2） 主语+动词的被动语态+to do
如：The technology behind RealCine is said to be virtual reality.
类似的动词还有：believe, report, suppose, know, prove 等。
二 情态动词和被动语态
1．在被动语态中用情态动词来表达能力，可能性，责任，允诺等。 如：Firefighter could be trained using RealCine.
2．情态动词被动语态的形式是：情态动词+be+动词的过去分词 如：The position of the viewer can be calculated at any time. 注意其它情态动词被动语态的用法： 主动语态 被动语态 Can touch can be touched May feel may be felt
Might not impress might not be impressed Could use could be used Should use should be used Ought to develop ought to be developed Must wear must be worn
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被动语态通常被用在科学报告中。
三 经常被用做被动语态的动词
1．一些经常被用做被动语态的动词可以充当形容词的作用.如：be bored with be born in/on be disappointed at /by be fascinated by be impressed at /by/with be interested in be set up by be situated in /on be surprised at/by 如：Andy was bored with listening to the same CD every day. I was born on a Wednesday.
My dad was disappointed by my test results.
People have always been fascinated by new technology. She was impressed at the number of points I scored. Some of my friends are interested in studying abroad. This new exhibition was set up by the Students’Union. Our school is situated in a quiet area.
They were surprised at the possibilities of the Internet. 这里的be都可以用become来取代。
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