01 How can mountains affect rainfall?
Answer and explanation
Correct answer: D. They force moist air to rise
Explanation: Answer: D, they force moist air to rise. When moisture-laden air reaches a mountain, the mountain slope makes the air move upward. As the air rises, it expands and cools. Cooler air cannot hold as much water vapour, so the vapour condenses into clouds. If condensation continues, rain falls, especially on the windward slope. This is called relief or orographic rainfall. A is wrong because mountains do not remove water from the sea. B is wrong because mountains do not stop sunlight. C is wrong because air continues to move around and over mountains. D is correct because upward movement and cooling of moist air can produce clouds and rainfall. Memory cue: moist air plus rising plus cooling can mean rain.