Air - Fill in the Blanks part 13

Fill in the blanks by choosing the correct words from the box.

          compressed         vacuum pump                oxygen

           gas                      balance                           carbon dioxide

1. Air is a -------- and so can be ------------- easily. (gas, compressed)

2. A ------------ removes air from containers. (vacuum pump)

3. Plants use -------- to make their food and give out ---------- (carbon dioxide,  oxygen)

4. Ears pop out in the mountains to ------- the air pressure inside and out side the ears. (balance)