—OK. From now on, I will spend money              .

    Natural resources that we use are things that come from the Earth.

    Our natural resources are limited(有限的）. This means that they will not1 forever. Some are renewable, like when you plant a new tree when you2 one down. Others are not renewable, like when you dig coal(煤）out of the3. Once it is used, it is gone.

    People realize the4 that the Earth's natural resources are limited, and people can do things to help conserve(节约）those resources. 5 you try to conserve a natural resource, you try to use less of it so it does not run out so 6One way that people conserve fuel, like gasoline, is by riding a bicycle or walking when the 7 is short instead of driving everywhere.

    Water is a very important natural resource because we all need it to stay 8. We can conserve water9 making sure that the pipes and taps do not leak(漏）. We can also make10 choices to conserve water, like only using the dishwasher or washing machine when they are full. Everyone can make contribution to protecting natural resources.

    There is a lot of salt on the Earth, and it mixes very well with water.

There is some salt in all water. Water on the land runs into lakes and rivers. These rivers run into the seas and oceans. They carry a little salt with them. Some of the ocean water moves into the air and clouds. It evaporates. Salt cannot evaporate. It stays in the oceans.

    The water in the oceans has more salt than river water. There is about 3. 5% salt in the ocean water. Some seas have more salt than others.

    Some of the water leaves the lakes. It evaporates, but the salt cannot. These lakes are very salty. There are two famous lakes like this. They are the Dead Sea in the Middle East and the Great Salt Lake in Utah(犹他州）in the United States. They are much saltier than the Atlantic Ocean（大西洋）and the Pacific Ocean(太平洋）.

—My uncle.

—Yes,             is dangerous to do that.