2. What happens to your muscles when you yawn?
- Our muscles will lengthen.
3. What usually happens when you see someone yawn? - It's contagious.
4. How long does a yawn last?
- We quckly close our mouth.
5. Why do Olympic runners yawn before a race?
- Runners are tired after a long race.
6. What other things are contagious?
- Some ills.
