Clouds are made of millions of very small drops of water. The drops move around all the time. When they hit each other, they join up. This is how they grow larger and heavier. When they are too heavy to stay in the air, they fall down as rain.
If it is very cold, the very small drops of water changes into ice. The piece of ice freeze together. When they get too heavy, they fall down as snow.
There are many different kinds of clouds. And they are different in shape. The thunderclouds are big and dark. Some clouds are like small white balls of cotton.
根据上文内容，判断正(T)误（F）
( ) 1. Clouds in the sky never move around.
( ) 2. When drops of water join up, they grow larger and heavier.
( ) 3. When clouds of water fall down, we get snow.
( ) 4. The thunderclouds are one kind of clouds.
( ) 5. Clouds in the sky are different in shape, size and colour.