而be used to doing意为“习惯做 ”，be可有各种时态；be used to do意为“ 被使用去
做 ,”为被动语态形式。be used for doing sth“用作 ”如：My father used to eating meat.我父亲过去起床晚，但现在不得不早起了。She is used to eating meat.她习惯吃肉。He wasn’t used to eating in a restaurant.他不习惯在饭店吃饭。A knife can be used for cutting things.(刀可以用来割东西)/
A knife can be used to cut things.(刀可以用来割东西)
【情态动词例题解析】
1、—________ you pass me a pen? I’d like to write down the phone number. —Sure. Here it is.
A. Can B. Need C. Might D. Must
【解析】由题干可知，本句表示请求、许可。答案：A
2、—May I go to the cinema, mum? — Certainly, but you ________ be back by 11 o’clock.
A. can B. may C. must D. need
【解析】由题意可知，此处并非表推测的用法，而是妈妈对孩子提出的要求，故选C,意为―必须‖。答案：C
3、You ______ get there by bus. A. don’t need B. needn’t to C. don’t need to D. need don’t to
【解析】由选项A可知need为实义动词，故应加上to才正确。选项B needn’t为情态动词，应去掉to，故选C.
4、You _______ worry about me. It’s nothing serious. A. can’t B. mustn’t C. needn’t D. won’t
【解析】由题干It’s nothing serious可推断，第一句意为―你不必为我担心‖，故选C。本题易错选B, mustn’t意为―禁止‖，故不正确。答案：C
5、—Excuse me. Is this the right way to the Summer Please? —Sorry, I’m not sure . But it _______ be.
A. might B.mustn’t C.can’t D.must
解析】考查情态动词might表推测的用法。―I’m not sure‖说明说话者的语气并不肯定，所以要用might。答案：A
6、The man in the office___be Mr. Black, because he went home just now.
A.mustn’t B.may not C.can’t D.needn’t
【解析】由下文he went home just now可知，作者判断办公室里那个人（不可能是Mr. Black。mustn’t意为―千万别‖，may not意为―可能不‖，needn’t意为―不必‖。can’t意为不可能，故选C。
7、—Can you go surfing with us this afternoon?
—I’d like to , but I __ look after my sister at home , because my mother is ill.
A.need B.must C.have to D.should
【解析】由题干my mother is ill为客观要求可知，选C.
8、—May I take this book out of the reading room? —______. Please read it here.