A Cloud of Hope and Danger

    In 2050, a small cloud floats through the air in a hospital operating room(手术室). In the room a patient, suffering from cancer, lies on a table. The cloud surrounds (包围) the patient, her body and filling her lungs (肺). The cloud is not smoke or steam. It is made of millions of microscopic robots called nano-robots(纳米机器人). These tiny robots move from cell(细胞) to cell in the body, destroying the cancer cells.

    Fighting cancer with nano-robots is only an idea today, scientists say that it would be possible in the future. Using nano-robots for good purposes such as fighting disease or repairing the environment may be the to many of today's problems.

    However, nano-robots could be a risk as well. Since nano-robots are so tiny, they will have to work in large teams of many thousands to 'many millions. For this reason, nano robots will have to be programmed to build . Scientists will not have the ability to build millions of nano-robots one by one.

    This to reproduce(复制)is making some scientists worried. What if something goes wrong in the programming? Quite a lot of crazy nan-orobots would be far than any disease. Some people think that if they get out of control, nan-orobots could destroy the Earth.

    What should be done? Should we continuenan-orobots or should we search for other methods? This is one of the many difficult that we have to make in the future.

Mom often says, "Cooking is an important skill, and it can be fun!" But I had no interest in cooking at all  I met with a cooking app（应用软件）. There are different kinds of recipes（菜谱）in the app. They offer detailed instructions  users can follow them step by step. Most of them even include photos or videos, which are quite useful for beginners. Last week, I picked up a popular recipe to cook fish. When I  , it was exactly what I wanted and tasted delicious. Then I tried more recipes. Now I can cook a couple of  . I find cooking is great fun and it seems that I  cooking. My plan is to invite my friends over next weekend and show them my new skills. I hope they will like my cooking.

Today, we still have some environmental problems. As a middle school student, we should do something to improve more environmental .

On the one hand, we ourselvesdestroy the environment, such as throwing the rubbish about. We canpart in some commonweal（公益）activities to plant more trees, for the trees are good to our environment. On the other hand, if someone does harm to the environment, like spitting on the ground or stepping on the grass, we can stop them from so, If there's a factory which destroys the environment, we can tell the relative（相关）department or the police about it.

All in all,  we are students, we can still do a lot to protect our environment, and we should take action from now on.