A formal letter is very different from an informal letter. Formal letters ___1___ to businesses, schools or government offices. ___2___ letters are for relatives, or former(以前的) teachers. You may write an informal letter by hand, but you should ___3___ a formal letter.
1. A. send B. are written C. write D. are dropped
2. A. Informal B. Formal C. Business D.Relative
3. A. copy B. type C. write D.share
【解析】1. 选B。该句缺少谓语动词，而写信应用被动语态。该句意为“正式书信是写给商业部门、学校……”。D虽用了被动，但搭配不当。drop sb a line为“给人写信(短信)”。
2. 选A。前面说的是正式书信，这里说的是写给亲戚、好友或以前的老师的，较随便，即非正式书信。
3. 选B。通过but可知，此处说的是非正式书信与正式书信的写作方式的不同，非正式书信可以手写，但正式书信要正规得多，得打字。
2．巧用因果关系线索解题
即根据上下文的因果关系进行推断，从而得出所需答案。如：
It was a strange noise that made the man ___1___ his car soon after he left a village ___2___ London. He got out of his car and ___3___ the wheels(车轮) carefully, but as he found nothing ___4___ he continued his way.
1. A. start B. stop C. slow D.speed
2. A. to B. for C. from D. of
3. A. repaired B. examined C. cleaned D.looked
4. A. wrong B. danger C. interesting D.matter
【解析】1. 选B。他在去伦敦的路上，一阵奇怪的声音驱使他把车停了下来。这可从He got out of his car…推测出来。
2. 选B。leave…for…是个固定短语，意为“离开……到……”。
3. 选B。在听到奇怪的声音后，他停下车来仔细检查轮胎(看看出现了什么问题)。
4. 选A。从下句“他又继续赶路了”可知，“因为他没有发现毛病”。nothing wrong意为“没有毛病”。
3．巧用具体示例线索解题
即根据文章中所提供的具体实例进行分析，将与具体示例有关的信息进行优选，将与具体示例无关的信息进行排除，从而便可得出所需答案。如：
Every student must wear their ___1___ when they are at school. There are ___2___ items of uniforms: suits, dresses, shorts, skirts and T-shirts. There are also Wasley schoolbags, caps and socks.
1. A. long hair B. thick glasses C. sports shoes D. school uniforms
2. A. much B. three C. many D. a lot
【解析】1. 选D。本段谈论的是在校生穿校服的事情，而不是穿运动鞋，蓄长发、戴墨镜并不是学校所提倡的。
2. 选C。suits, dresses, shorts, skirts and T-shirts等是服装的个例，前面只有填“校服”才与之相配。
