Please help!!

A swamp is like a huge sponge. The soil in the swamp can hold a lot of water. In this way, the swamp prevents flooding during the rainy season and provides water in the dry season. So the swamp can be called a natural reservoir. This process gives a lot of benefits to animals like me that always need water.

According to the passage, which world can contain all the other four?

1. benefit

2. water

3. sponge

4. swamp

5. reservoir