The world is not hungry, but it is thirsty. It seems strange that nearly 3/4 of the earth is covered with 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 3% of the water that comes from rivers and lakes. And we can’t even use all of that, because some of it has been polluted(污染).

Now more water is needed. The problem is: Can we avoid a serious water shortage later on? Firstly, we should all learn how to save water. Secondly, we should find out the ways to reuse it. Scientists have always been making study in this field. Today, in most large cities, water is used only once and then runs to the sea or rivers. But it can be used again. Even if every large city reused its water, still there would not be enough. What could people turn to next?

The sea seems to have the best answer. There is a lot of water in the sea. All that needs to be done is to get the salt out of the sea water. This is expensive, but it’s already in use in many parts of the world. Scientist are trying to find a cheaper way to do it. So you see, if we can find a way out, we’ll be in no danger of drying up.

The smallest body of water is the stream(溪流）,a natural body of water that is found above ground and is often called a creek（河湾）as well. A river is a larger body of water that moves above ground, in a particular direction, and usually has a large amount of water in it.   Rivers often go into other bodies of water. For example, The Chanjiang River goes into the sea. A lake is a large body of water that is completely surrounded（环绕)by land. A pond（池塘）is the same thing, only with less water and a smaller size. No one can tell you how big a pond can become before it is called a lake. A sea is a large body of water that is surrounded by land and connected to another body of water. The Caspian Sea（里海）is one that is surrounded by land. The Mediterranean Sea（地中海）is one that connected to another body of water, the Atlantic Ocean（大西洋）Why are these bodies of water called seas but not oceans? Geographers（地理学家）don't have a really good reason. An ocean, which is the largest body of water on the Earth, is generally thought to have no borders（边界）

You may have heard the saying “The Yangtze River is China’s mother river.” The main route of the Yangtze is almost 6,400 km long. As the world’s third-longest river, it covers one-fifth of China’s land area. The Yangtze River Economic Zone (长江经济带) covers 11 provinces and cities, making up about two-fifths of China’s total population and GDP.

On December 26, China passed the Yangtze River Protection Law, which took effect on March 1, 2021. It is the first law to protect a waterway in China.

The “mother river” is in great need of protection because something is wrong with it. For example, because of overfishing and water pollution, the river’s Chinese paddlefish (白鲟) has died out after surviving for 150 million years. There’re also desertified (荒漠化的) land and soil pollution near the upstream part of the river in Qinghai province.

The Yangtze River Protection Law includes bans (禁止) on activity that could damage the river. It also includes heavier punishments for those who don’t follow the law.

According to the law, fishing will be banned in all of the Yangtze’s natural waterways. Those who are caught fishing will be fined 50,000 to 500,000 yuan.

Sand mining (采沙) will be strictly limited in the river valley. Many companies are mining sand along the river, as sand is a rare resource. However, the water levels on this river have dropped because of this, which has made the river’s water quality become worse.

Companies operating along the river will need to focus on green development. Companies that produce dangerous chemicals will be moved to other places, the law says.