Have you ever asked yourself why children go to school? You will     1     (probable) say that they go to learn languages, history, science and some other knowledge. That’s quite true, but do you know why they learn these     2     (thing)?

We send our children to school to prepare them    3     the future when they grow up and have to work for     4     (they). Nearly everything they study at school has some practical use in their life. But is that     5     only reason why they go to school?

Actually, there is more in education than just    6     (learn) facts. We go to school above all to learn how to learn, so that when we graduate we can continue to learn.     7     a man really knows how to learn, he will be     8     (success). Because when he has to do something new, he will not only be able     9     (do) it well himself, but he will also be able to teach others how to do it in the     10     (good) way. So the purpose of schools is not to teach languages, history, science, etc., but to teach students the way to learn.

Nowadays the virtual choir is popular with people.They have the opportunity     1     (sing) together with hundreds of other people.Anyone can take part in a virtual choir from anywhere—all you need is a video camera and     2     Internet connection. They record themselves when     3     (perform) alone on video.These videos     4     (upload) onto the Internet, and then put together into one video.The virtual choir has proved to be a positive influence on the lives of many people.Eric Whitacre, the creator of the virtual choir，fell in love     5     music in the university.In 1997, he received a master’s degree in musical composition.Over the next 10 years, Whitacre’s original compositions began to become popular.This led to the    6     (create) of the virtual choir.In 2009, Whitacre received a video of a girl     7     was singing one of his works.     8     (inspire), he founded his first virtual choir. Since then, the virtual choir     9     (become) a worldwide phenomenon. The virtual choir is making the world a     10     (good) place.

When you take a walk in any of     1     cities in the west, you often see a lot of people walking with dogs. It is still true that the dog is the most useful and faithful animal in the world. But     2     reasons why people keep     3     dog have changed. In the old days, people used to train dogs to protect themselves against the attacks by other beasts. And later they came to realize that the dog was not only useful but willing to obey its master. For example, when people used dogs for hunting the dogs would not eat what they caught without permission. But now people in the city need not protect themselves against attacks of animals. Why do they keep dogs, then? Some people keep dogs to protect themselves from robbery, but     4     most important reason is for companionship. For a child, a dog is his best friend when he has no friends to play with; for young couples, a dog is their child when they have no children. So     5     main reason why people keep dogs has changed from protection to friendship.

On 20 December, a series of huge waves caused by     1     undersea earthquake raced across the ocean near Goldshore and left thousands     2     (die) . Luckily, due to a ten-year-old girl's basic knowledge of tsunamis, Goldshore Beach became the only local beach     3     (survive) the disaster without any loss of life.

On that day, people were walking, running or simply sitting on the sandy beach, enjoying the warm sea air and the soft wind that brushed their hair     4     something odd happened. The water was frothy, like the bubbles on the top of a beer. It wasn't calm, instead, it was just coming in and in.     5     (see) this, the little girl named Sabrina realized that these were the     6       (sign) of an approaching tsunami. Though     7     (frighten), she kept her head and warned her parents and a safety officer     8     the danger. At last, the beach was     9     (rapid ) cleared of people just before the huge waves     10     (crash) into the coast.

It's time to reconsider food. Around the globe, food problems threaten wildlife, wild places and the planet itself. Today, 7. 3 billion people consume 1. 6 times     1     the earth's natural resources can supply. By 2050, the world's population     2       (reach) 9 billion and the demand for food will double.

So how do we produce more food for more people without     3     (expand) the land and water already in use? We can't double the amount of food.       4     (fortunate), we don't have to—we just have to double the amount of food available now instead.       5     short, we must freeze the footprint of food.

In the near- term, food production is enough to provide for all, but it doesn't reach everyone who needs it. About 1. 3 billion tons of food     6     (waste) each year—four times the amount     7     (need) to feed the more than 800 million people who are     8     (hunger) .

By improving efficiency and productivity while reducing waste and shifting consumption     9     (pattern), we can produce enough food for everyone by 2050 on roughly     10     same amount of land we use now.