| A．clean the floor | B．wash the hands | C．brush the teeth |
Where does rain come from? Rain always comes from clouds. But where do clouds come from? How does water get into the sky?
Think about your bathroom. There is hot water in your bath. Steam(蒸汽)goes up from the hot water. The steam makes small clouds in the bathroom. These warm clouds meet the cold walls and windows, and then we see small drops of water on the walls and windows.
The world is like your bathroom. The sun shines on the ocean. The water in the ocean becomes warm. Some of the water goes up into the sky and makes clouds. The wind carries the clouds for hundreds of kilometers(千米). Then the clouds meet cold air in the sky, and we see drops of water. The drops of water are rain.
The rain falls and runs into rivers. Rivers run into the ocean. And the water from the ocean makes clouds and more rain. So water is always moving from the ocean to clouds, then to rivers and again to the ocean.
1．Rain comes from clouds. ( )| A．always | B．sometimes | C．never |
| A．rain | B．steam | C．drops |
| A．move with the wind | B．come from cold water | C．do not travel a long way |
| A．brush | B．brushes | C．clean |
| A．on | B．in | C．from |
Do you know anything about water? You may say, "I 1．water every day." When you look at the map of the 2．, you can find there is more water than land. But the water in the 3．is salty. We can't drink this salty water. There are also a lot of very small 4．things in the sea. They live with fish and 5．.
| A．cook | B．cooking | C．cooks |
搜索
