Question

1. the majority of the earths atmosphere is composed of nitrogen and oxygen,
2. greenhouse gases comprise only a tiny fraction of the atmosphere.
3. all greenhouse gases are created as a result of human activity.

Explanation:

1. Nitrogen (about 78%) and oxygen (about 21%) make up the majority of Earth's atmosphere, so statement 2 is true.
2. Green - house gases like carbon - dioxide, methane, etc. are a small fraction of the atmosphere, so the first part of statement 3 is true. But some greenhouse gases, like water vapor, occur naturally and are not solely the result of human activity, so statement 3 is false.

Answer:

1. T
2. T
3. F