Помогите с английском

### 9 Complete the sentences with the correct form of the verb in the box.

1. If you heat water to 100°C, it **boils**.
2. If you cool water to 0°C, it **freezes**.
3. If a heater warms the air in a room, the air **rises**.
4. If an air conditioner cools the air in a room, the air **sinks**.
5. If you heat steel bars to 1400°C, they **melt**.
6. If you pull a copper wire very hard, it **stretches**.

### 10 Identify the material from the description.

1. Sunglasses are made of this material. It's a hard and tough plastic. **Polycarbonate**
2. You can stretch this material and you can bend it, but it doesn't break. **Rubber**
3. You can heat this material to a high temperature, but it doesn't burn or melt. They use it in spark plugs. **Ceramic**
4. Parts of aeroplanes are made of this material. It's a strong, light, corrosion-resistant metal. **Aluminium**