We all get tired when night comes. Then we need to sleep. That is why we need beds. But not all beds are the same. There are many kinds of beds.
One kind of bed is the bunk bed. Bunk beds are two beds placed one on top of the other. This kind of bed doesn’t take as much room as two beds side by side. It’s a nice way to sleep if two or more children are sleeping in the same room. That is why families with many children use them. The passage is mainly about ______.
A. the importance of bunk beds B. the difference between cots and mats
C. several different kinds of beds D. the role that water beds play

A water bed can be a lot of fun. It is a very big bag that’s filled with water. The water can be made nice and warm. You move up and down as the water moves. It’s something like being on a boat. It rocks you to sleep.A cot is a very light bed. When it’s not being used, you can fold it up and put it out of the way. Then you can take it out again when you need it. You can use it for a friend. A cot is just right for someone who is sleeping over,In some places people sleep on mats. The mats are made of long pieces of grass. People take them out at night on the floor. In the morning people take them up off the floor and roll them up. Think of how much room a house has with no beds!