Q: Fact: the greenhouse effect is when carbon in the air heats a planet 's atmosphere
Question: Greenhouses work because

A: air retains humidity and warmth

Q: Fact: fertilizers are a source of pollution
Question: What are some of the risks of using fertilizer?

A: Damaging the planet

Q: Fact: the mass of a planet causes the pull of gravity on that planet
Question: the mass of a planet causes

A: matter to approach

Q: Fact: as the roughness of something increases , the friction of that something will increase when its surface moves against another surface
Question: If I run my finger across a sheet of plain paper and a sheet of sand paper, which will have greater friction?

A:
the sand paper