—Yes, there are ________.

There is jam in the bottle.

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.

The world is not hungry, but it is thirsty. It (seem) strange that nearly 3/4 of the earth is covered water while we say we are short of（短缺）water. Why? Because about 97% of water on the earth is sea water which we can't drink or (use) for watering plants directly（直接地）. Man can only drink and use the other 3% of the water that comes rivers and lakes. And we can't even use all of that, because some of it is (pollute).

Now more water is needed. The problem is: Can we avoid (避免) a serious water shortage later on? First, we should all learn how (save) water. Turn the tap off while (brush) your teeth, washing your hands, doing the dishes, and so on. Second, we should find the ways to reuse it. Scientists always make studies in the field. Today, in most large (city) water is used only once and then runs to the sea or rivers. But it can be used again. Even if(即使) every large city reused (it) water, still there would not be enough. From now on, everyone should save the water.

there is water, you will live for a few days.

to turn off the tap.