［考点］however的用法。

［透视］however①作副词时，表示前后对比，可位于句首，句中或句末，并用逗号隔开。而but是连词，连接并列句，指前后两者相反。②作连词时，与no matter how相同，引导让步状语从句。

［考点］现在进行时的用法。

［透视］现在进行时既可表示动作正在进行，也可表示将要发生的动作。注意其与一般现在时的区别。

［考点］except, except for, except that (when．．．), but, besides等表示"除......之外"的区别。

［透视］①except (but)指"除去......(不包括在整体内)"，而besides则指"除......之外，还有（包括在整体内）"。②except for指除去不同类型的东西；except that(when)后接从句。

· 课堂同步练习 ·

一、单句改错

　　1. I met the lady in the park which showed us how to cook beancurd.

　　2. This is the house which he lived when he was a child.

　　3. They were very poor that they could not send him to school.

　　4. He has two sons, all of whom are doctors.

　　5. The watches which was repaired last week have not been sent back.

二、易错题练习:

1. This is the mountain village ______ we visited the other day.

　　A. which B. in which C. where D. when

2. A child ______ parents are dead is called an orphan.

　　A. which B. his C. whose D. with

3. Do you know the date _____ Lincoln was born?

　　A. which B. when C. where D. that

4. She thought I was talking about her daughter, _____, in fact, I was talking about mydaughter.

　　A. whom B. where C. which D. while

5. Tom's mother kept telling him that he should work harder, but _____ didn't help.

　　A. he B. which C. she D. it

6. The gentleman _____ you told me yesterday proved to be a thief. 　

A. who B. about whom C. whom D. with whom

7. John shut everybody out of the kitchen ______ he could prepare his grand surprise for the party.

　　A. which B. when C. so that D. as if

8. She found her calculator ________ she lost it.

where B. when C. in which D. that