The underlined word in each sentence is incorrect. Write the correct word.

1. In the atmosphere, the density of air increases with increase in height.
2. All weather phenomena occurs in the stratosphere.
3. A greenhouse is a brick house used to grow plants in cold areas.
4. A rise in sea level due to global warming will cause flooding of mountainous areas.
5. Light year is used to measure the thickness of ozone layer.

Which of these gases is found in the lower layers of the atmosphere?

1. helium
2. hydrogen
3. neon
4. oxygen

Which of these is a greenhouse gas?

1. carbon dioxide
2. oxygen
3. hydrogen
4. nitrogen

Which of these activities do not produce greenhouse gases?

1. energy use
2. agriculture
3. afforestation
4. industrial process