Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

1. A plunger is used to clear blocked sinks and drains.

2.When a plunger is pushed firmly against a flat surface, air is forced out of the rubber sucker. The air pressure inside is .

3.The air pressure outside the rubber sucker is than the air pressure in the rubber sucker.

4. The plunger cannot be pulled off the surface unless the seal around the edge is broken.