WONDER #2043: How Can You Breathe Where Trees Don’t Grow?

Question 1 of 3

The point beyond which trees can’t survive is known as the what?

  1. border
  2. arcticore
  3. treeline
  4. desert

Question 2 of 3

Oxygen makes up about what percentage of Earth’s atmosphere?

  1. 5%
  2. 15%
  3. 21%
  4. 47%

Question 3 of 3

In addition to trees, what is responsible for producing a large percentage of Earth’s oxygen?

  1. cows
  2. solar panels
  3. windmills
  4. phytoplankton

Check your answers online at https://www.wonderopolis.org/wonder/how-can-you-breathe-where-trees-dont-grow.