Here are the sentences completed with the correct forms of the words from the box:

1. The water needs to be **boiled** to get to a temperature of 100 degrees.
2. By **covering** the place where you blow into the balloon, the air stays inside in the balloon.
3. To start the experiment, you need to **wrap** the glass with cardboard.
4. **Tie** the paper around the bottle and leave it for five minutes.
5. After you have **rubbed** the balloon on your hair, move it away from the can and watch the can move towards the balloon.