New words：

deaf [def] adj. 聋的；不愿听；不去注意

Sample Sentences：

She was born deaf.
He was deaf to all advice.
She was almost blind and deaf, but her heart was full of courage.

New words：

chalk [tʃɔk]
n.粉笔
v.用粉笔写（或画）

Sample Sentences：

The teacher wrote on the blackboard with a piece of chalk.
She wiped the chalk marks off the blackboard with an eraser.
He chalked a math problem on the blackboard and asked us to solve it.

New words：

unit [ˈjunɪt] n. 单元；单位

Sample Sentences：

The basic unit of length is the metre.
The basic unit of society is the family.
We are studying Unit 5 in the biology textbook.
The team was divided into smaller working units.

New words：

balance [ˈbæləns] n.余额，余数，结存；天平

Sample Sentences：

They were due to pay the balance on delivery.
The chemist measured the powder on a balance.
Don’t forget to check your phone’s data balance.
I'd like to check the balance in my account please.
The balance is a basic tool in physics experiments.

New words：

item [ˈaɪtəm] n.项目；一件商品（或物品）；新闻中的）一则、一条；条款

Sample Sentences：

What's the next item on the agenda?
The store offers free shipping for items over $50.
The lawyer reviewed each item in the agreement.
There was an item about the accident in the news.