Must wear must be worn
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。
牛津高中英语－模块五
第一单元
一 动词不定式：带to的动词不定式
带to-的动词不定式的结构是to+动词原形，如，to do, to work.它可以单独使用，也可以组成动词不定式短语。
如：I was determined to be cheerful.
1．带to-的动词不定式可以做：
1）句子的主语
如：To find a best friend is difficult. = It is difficult to find a best friend.
2）句子的宾语
如：I need to sleep for eight hours every night.
宾语不足语
如：I asked him to come over.
定语
如：I have a very important meeting to attend.
同位语
如：His intention was to cheer me up.
状语
如：My dad arranged some swimming lessons to surprise me.
2．带to-的动词不定式有进行时态和完成时态
如：Things seem to be getting better.
John pretended not to have seen me.
二 动词不定式：不带to的动词不定式
1．可用于不带to的动词不定式的动词有：
