II. DIRECTION: B. Choose the BEST word that completes the sentence. (5pts)
1. Atmosphere act as (blanket, wall, light) of the earth.
2. The upper limit of the atmosphere is called (stratosphere, troposphere, exosphere)
3. The layer after the mesosphere where air is very thin is called the (exosphere, stratosphere, thermosphere).
4. The gas that makes up most of the Earth’s atmosphere is (Oxygen, Nitrogen, Carbon Dioxide)
5. (Ozone, Meteors, Auroras) layer protects us from the harmful radiation of the sun.