### 名词变复数发音变化
1. 清辅音后fa[s]
> e.g. shops/books
2. [s][z][S][Z][tS][dZ]之后发[iz]
> e.g. boxes/watches/blouses
3. [t]后发[ts],[d]后发[dz]
> e.g. cats/beds
4. 其他音(元音及规则提及外的辅音)后发[z]
> e.g.ties/dogs
简单记忆：清清、浊浊、元浊
## Lesson 21
1. give v. 给
```
记：give sb sth 授人予物
give sth to sb 授物予人
e.g. Give me the book.
Give the book to me.
记：give sb a hand.帮某人一个忙，，给某人鼓掌
e.g. Give her a hand,please.
give it a try.试一下
give me a call .给我打电话
```
2. one pron 一个 用于值一个提到过的或已经知道的人或物
```
e.g. Give me the book.
This one?
复数 ones
Give me the books.
The red ones.
```
3. which 哪一个
whice one?
