Question

creating lake-effect snow

situated on lake erie, the city of buffalo, new york, is one of the snowiest cities in the united states. like other cities on large lakes, it is subject to a phenomenon called lake-effect snow. water retains heat, so lake water is often warmer than the air. in the lake effect, cold air moves over warmer lake water, initiating a process that can produce large snowstorms. moisture from the lake evaporates into the cold air, warming it. because warm air is less dense than cold air, it begins to rise. as it rises and moves away from the lake, it cools down. as the air cools, moisture condenses and forms into clouds. if the temperature is cold enough, the moisture falls to the ground as snow.

what is the main, or central, idea of the passage?

buffalo, new york, gets more snow than most cities in the united states.

in the lake effect, warm air, which is lighter than cold air, rises and moves away.

when cold air moves over the warmer water of a lake, lake-effect snow can be produced.

Explanation:

The passage explains the process of lake - effect snow: cold air moves over warmer lake water, moisture evaporates into the cold air, the warm air (less dense than cold air) rises, cools, and the moisture condenses to form clouds and snow. Among the options, the third option (Buffalo, New York, gets more snow than most cities in the United States) is just an example of a city affected by lake - effect snow. The second option describes a part of the process but not the main idea. The first option (When cold air moves over the warmer water of a lake, lake - effect snow can be produced) accurately captures the main idea of how lake - effect snow is formed, which is the central idea of the passage.

Answer:

When cold air moves over the warmer water of a lake, lake - effect snow can be produced.