Serious internal wounds (内部的伤口)are hard to repair. They often require surgical operations (外科手术). But a new kind of glue might make these wounds easier to repair.

The glue is called MeTro. It can be used in small surgical operations. It was developed by a group of scientists from Australia and America, Daily reported.

Once used for a wound, MeTro can cure (治愈)it in one minute with the help of UV light. MeTro is made from special proteins (蛋白质).It is very elastic (有弹性的). This makes it possible to use it to cure wounded body parts. These body parts often change shape, so their wounds are more likely to reopen.

There is still a long way to go before the glue can be safely used on humans. But its future is bright. It could be used to cure serious internal wounds in emergency (紧急的)situations, such as after a car accident, Anthony Weiss from the University of Sydney told Science Daily.

People have been using the wind’s energy for a long, long time. More than 5,000 years ago, ancient Egyptians made boats powered by the wind. In 200 B.C., people used windmills(风车)in China.

Today, we collect the wind’s energy with wind turbines(涡轮). A turbine is similar to a windmill; it is a very tall tower with two or three blades (叶片) at the top. These blades are turned by the wind. The blades turn a generator(发电机) located inside the tower, which creates power.

Groups of wind turbines are known as wind farms. Wind farms can be found near farmland, in narrow mountain passes and even in the ocean, where there are stronger winds. Wind farms create power for nearby homes, schools and other buildings.

In places like the Midwest and along coasts, winds can provide cheap power. Another great advantage of wind power is that it is a clean form of energy. Wind turbines do not burn oil or coal and do not pollute the air.

Wind is not always an ideal source of energy, however. Wind speed changes from time to time, depending on the time of day, weather and location. Wind turbines can be also dangerous for bats and birds. These animals cannot always tell how fast the blades are moving and crash into them.

The wind’s energy is important for humans. People in Egypt made wind powered boats 【小题1】 5,000 years ago. People in China used windmills in 200 B.C. Today the wind’s energy is collected with turbines, which are tall windmill-like towers with 【小题2】 blades at the top and a generator wide Wind farms can be found in places where there are stronger winds. The power is 【小题3】 for nearby homes, schools and other buildings. Winds produce power at a low 【小题4】 in certain areas, and they don’t cause air pollution. However, wind speed doesn’t remain at the same 【小题5】 all the time, and wind turbines can be dangerous for animals.

Are electric cars good for the Earth? Many of us would probably say “Yes”. But 17-year-old Robert Sansone knows the answer to that question isn’t so simple.

Many people call Sansone a natural-born engineer. It is not surprising if you look at what the boy has done. He has completed over 60 engineering projects in his free time.

Several years ago, Sansone watched a video about how the motors (发动机) of electric cars are made. Most of them use rare-earth metals (稀土金属). These materials are very expensive. Even worse, they are often collected in ways that are harmful to the Earth.

“Is there a green way to make electric motors?” Sansone thought. He had heard of the synchronous reluctance (同步磁阻) motor. This kind of motor does not require rare-earth materials. However, it isn’t strong enough to power a car. Sansone decided to improve its performance.

Over the following year, things didn’t go smoothly. He failed fourteen times before coming up with a working model. The model is about 40 percent more powerful than a traditional one.

Sansone’s efforts paid off. He took part in the science competition with his new motor and he won the first prize.

However, it is far from perfect. There is still a big problem: It is difficult to make. So Sansone has continued to improve his motor.

Many people believe Sansone’s design will become widely used one day. When that day arrives, we will finally be able to say that electric cars are good for the Earth.