1. Which of the following refers to the lowest layer of the atmosphere?
A.Exosphere
B. stratosphere
C. thermosphere
D.troposphere
2. Which of the following refers to the layer where ozone is located?
A.Exosphere
B. stratosphere
C. thermosphere
D. troposphere
3. Which of the following statements is true?
A.Argon is a natural greenhouse gas.
B.Water vapor is a natural greenhouse gas.
C.Oxygen has the highest concentration in the atmosphere.
D.Nitrogen has the lowest concentration in the atmosphere.
4.What drives all life processes on Earth?
A.atmosphere
B. meteorology
C. photosynthesis
D. solar energy
5. Which gas accounts for around 21% of the atmosphere?
A.carbon dioxide
B. helium
C. nitrogen
D. oxygen​