二、阅读与回答问题
Weather is important as it influences many things in people's life. Temperatures, wind, rain and snow are all parts of weather.
Weather is the condition of the atmosphere (大气) at a particular (特别的) place and time. The atmosphere is mostly made of air and wind is air which moves quickly. Heat from the sun makes the air move around. Hot air rises, leaving a space behind. Cooler air goes into that space. So air is always moving around the earth. The moving air pushes clouds along with it, making them travel across the sky.
Rain can fall from clouds when the air temperature is above 0°C. The water vapour (水蒸气) in clouds cools and becomes raindrops. The raindrops get bigger and heavier until they fall from the cloud. If the temperature is below freezing, tiny ice crystals (结晶) start to form in clouds. When the ice crystals fall from the cloud, they stick together to make beautiful snowflakes (雪花). Rain and snow are both important for life on earth. They bring water back into lakes, rivers and seas.
1. What is weather?
It's the condition of the atmosphere at a particular place and time.
2. What is the atmosphere made of?
It is mostly made of air.
3. What can fall from clouds when the temperature is above 0°C?
Rain.
4. How do snowflakes form?
The ice crystals fall from the cloud and stick together.
5. Why are rain and snow important for life on earth?
Because they bring water back into lakes, rivers and seas.
答案：1. It's the condition of the atmosphere at a particular place and time.
2. It is mostly made of air.
3. Rain.
4. The ice crystals fall from the cloud and stick together.
5. Because they bring water back into lakes, rivers and seas.
