Question

earths _ helps spread the suns heat around the planet, keeping it from getting too hot or too cold in one spot.
earths air is mostly _ (about 78%) and oxygen (about 21%).
the _ layer in earths upper atmosphere blocks most of the harmful ultraviolet (uv) rays from the sun.
water vapor, carbon dioxide, and methane are types of _ gases that trap heat in earths air.

Explanation:

• For the first card, the atmosphere helps spread the Sun's heat.
• For the second card, Earth's air is mostly nitrogen (about 78%) and oxygen.
• For the third card, the ozone layer blocks UV rays.
• For the fourth card, water vapor, carbon dioxide, and methane are greenhouse gases.

Answer:

1. atmosphere
2. nitrogen
3. ozone
4. greenhouse