4

Victoria Falls, Zimbabwe/Zambia

3

Pollution

4

Felix's Independence Day

3

Firefighter

3

Bus Driver

3

Space Exploration

4

How they Work? Trains

3

Neil Armstrong

3

Meteorites, Meteoroids, and Meteors

3

Comets

4

Hoover Dam

4

Okavango Delta, Botswana

2

Who Works Here?

4

Gorillas and Other Primates

3

Astronauts

4

Maddy's New Hampshire Diary

4

Mount Fuji, Japan

3

Motion

4

Niagara Falls

3

Police Officer