从方框中选出合适的句子，填在文章的空缺处
We should not use more water than we actually need. If we do, we will not have enough water in the future. It is not a difficult question to answer. If we remove more fresh water than nature replaces, we have taken too much.
Many cities run campaigns(运动) to get people to stop wasting water. They show them ways they can cut back on water use. What's more, they carry out programs that offer money to reduce water use. For example, they give people shower heads and toilets that use less water.
Another threat (威胁) to our water supply is pollution. When our sources of fresh water get polluted, we can no longer use this water. This also endangers(危及) the animals that depend on the water.
We can save lots of water by not letting taps(水龙头) run while we brush our teeth or by turning off taps right after washing hands. By collecting cold water when we're taking warm showers, we can also save water. In this way, we can make full use of water.
A. However, just how much is too much?
B. There are several things we can do to save water.
C. Finally, they make laws to control the use of water.
D. We don't have to let the cold water run until it gets warm.
E. They also increase water bills for people who use too much.