WONDER #35: Why Do You Yawn?
Question 1 of 3
Scientists have observed contagious yawning in which animal?
- chimpanzee
- horse
- elephant
- camel
Question 2 of 3
Oily substances that lubricate the lungs and prevent them from collapsing are called what?
- lungricants
- lubrifactants
- surfactants
- petroils
Question 3 of 3
When do most human beings begin yawning?
- before birth
- 1 year old
- 3 years old
- 5 years old
Check your answers online at https://wonderopolis.org/wonder/Why-Do-You-Yawn.