1. the process by which species change over time is called

Evolution

Explanation:

Whenever a species changes over a period of time, it's called Evolution, which is (normally) driven by Natural Selection.

you and your brother should be dizygotic twins (fraternal) twins since identical twins can only be one gender: boy and boy   or   girl and girl.

significant amounts of nitrogen oxides, carbon monoxide, and other pollution

explanation:

passenger vehicles are a major pollution contributor, producing significant amounts of nitrogen oxides, carbon monoxide, and other pollution. in 2013, transportation contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air.