Read the surprising facts about your body and complete the following sentences using the passive.

Gap-fill exercise

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!
   are damaged (extensively)      are estimated to live on one square inch of our skin      are produced by humans only      are used to frown      are used to smile      is consumed by the brain      is made up of around 7,000,000,000,000,000,000,000,000,000 (7 octillion) atoms      is pumped through our body every day (by the heart)   
SURPRISING FACTS ABOUT YOUR BODY

- Nerve signals to and from the brain can travel as fast as 170 miles or 273 kilometres per hour.
- The brain consumes the same amount of power as a 10-watt light bulb.
- A simple, moderately severe sunburn damages the blood vessels extensively.
- About 7,000,000,000,000,000,000,000,000,000 (7 octillion) atoms make up your body.
- A heart pumps about 2,000 gallons, or 7570 litres, of blood through our bodies every day.
- We use 17 muscles to smile and 43 to frown.
- Scientists estimate about 32 million bacteria live on one square inch (2,5cm2) of our skin.
- Only humans produce emotional tears.

1. The same amount of power as a 10-watt light bulb .
2. The blood vessels .
3. Your body .
4. 2,000 gallons (around 7570 litres) of blood .
5. 17 muscles and 43 .
6. 32 million bacteria .
7. Emotional tears .