1. For each missing word or phrase, circle the choice that correctly completes the sentence. The three main gases that trap heat in Earth's atmosphere are (carbon dioxide / oxygen / nitrogen / hydrogen), methane, and water vapor. They contribute to the (climate / ecosystem / greenhouse / biosphere) effect, which makes Earth's temperatures warmer than they would be otherwise.

Carbon Dioxide; Greenhouse

Explanation:

Carbon dioxide, methane, and water vapor all trap heat in the Earth's atmosphere. Because they are trapping the gasses in the atmosphere, they are contributing to the Greenhouse effect, which makes Earth's temperatures hotter/warmer. The "Greenhouse" part is saying that everything underneath the Earth's atmosphere is "housing" the heat and keeping the heat in.

answer: c.

explanation:

ok yes, but what is the question? as soon as you ask the actual question i will answer it. : )