WONDER #35: Why Do You Yawn?

Question 1 of 3

Scientists have observed contagious yawning in which animal?

1. chimpanzee
2. horse
3. elephant
4. camel

Question 2 of 3

Oily substances that lubricate the lungs and prevent them from collapsing are called what?

1. lungricants
2. lubrifactants
3. surfactants
4. petroils

Question 3 of 3

When do most human beings begin yawning?

1. before birth
2. 1 year old
3. 3 years old
4. 5 years old

Check your answers online at https://www.wonderopolis.org/wonder/Why-Do-You-Yawn.