Lake Victoria is the largest lake in Africa. It is also the second largest lake in the world. It is an important lake because it is one of the sources(源头) for the longest river in the world, the Nile River. Lake Victoria provides a source of water, food, and power(电力) for several African countries. Lake Victoria is a big part of African life.
   Unfortunately, Lake Victoria has a problem. It is shrinking. There are several power stations at Lake Victoria in Uganda. These are on the Nile River, and besides producing power, they keep the water of the lake at a certain level. For the past forty years, that level has been 11.9 meters. Over the last several years, the water level has dropped by about 2.5 meters. There seem to be several reasons for this drop.
   One possible reason is drought(干旱). Drought has been very bad in the area since 2000. Lake Victoria gets all of its water from rain, so the drought means less water in the lake.
   However, some environmentalists believe that the real problem is the power plants(工厂) on Lake Victoria. Uganda depends on those power plants for most of its power, and they made the power plants larger in 2000. Many people believe the power plants have been taking too much water off Lake Victoria. As a result, they have been asked to use less water until Lake Victoria goes back to its old level.
   Whether the low water level is caused by drought or power plants, the result is the same. This is already a poor area of Africa, where many people live a really hard life. People, animals and plants around Lake Victoria will suffer even more from low water levels on the lake. Many people need Lake Victoria for fishing or growing food. Fish need the water to live, and animals need it for water. Plants around the lake will die without the water, and then more animals and people will suffer. Unless the lake fills soon, many people will suffer and die.

阅读下面图表,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

    There will be three kids movies in theaters. Let's know the main idea of them first.

Friends with Kids was written and directed by Jennifer Westfeldt. The movie is a comedy about a group of people at that moment in life when children arrive and everything changes. The last two singles in the group, Wesffeldt and Adam Scott, see the result that kids have brought to their friends' life and want to know if there's a better way. They make up their mind to make a test—to keep a kid alone and meet other people together.

The special "test" causes everyone to question the nature of friendship, family and true love. This movie helps you think more about the love for your parents, for your child and so on.

More about the movie:

Release (发行) Date: Feb. 20, 2015

Directed by: Jennifer Wesffeldt

Made by: Joshua Astrachan

Written by: Jennifer Westfeldt

Do you like watching TV or playing computer games? How long do you use your phone a day? We call the time we spend on TV, computers and mobile phones" screen time".

In a study(研究) in Australia, scientists (科学家) ask 577,000 children how much time they spend on screens, schoolwork and sports every day. They find about 68% of them spend more than(超过) two hours on screens.

Two hours of screen time a day is bad for children's health. The study shows harm starts after 75 minutes of screen time for girls and 105 minutes for boys. Why is that? That's because the study shows that boys take more exercise than girls." In our study, 24% of boys spend an hour a day getting exercise, but only 14% of girls do that," Dr Khan said.

So it is important for children to balance(平衡) their time. Tom Hindhaugh has a" three- time" system for his son Patrick. That is a" go time" for schoolwork,a" slow time" to play computer games or talk with friends on the Internet, and a" green time" for getting exercise." We need to get children to do more exercise. They can walk, ride a bike or play football," he said." Anyway, Patrick is very happy and healthy."

Around the world more and more people are taking part in dangerous sports and activities. I would consider bungee jumping（蹦极）to be a good example of such an activity. You jump from a high place, 200 meters above the ground with an elastic（有弹性的）rope tied to your ankles. You fall at up to 150 kilometers an hour until the rope stops you from hitting the ground. It is said that about 2 million people around the world have now tried bungee jumping. Other activities which most people would say are as risky as bungee jumping include jumping from tall buildings and diving into the sea from the top of high cliffs（悬崖）. 

Why do people take part in such activities? Some psychologists suggest that it is because life in modern society has become safe and boring. 

Nowadays, according to many people, life offers little excitement. They live and work in comparatively safe conditions （条件）：They buy food in shops; and there are doctors and hospitals to look after them if they become ill. The answer for some of these people is to look for danger in activities such as bungee jumping. 

Do you know your mobile phone number well? You may sometimes find it hard to remember your number. That's because China has the longest mobile phone numbers in the world. Why is that? 

The 11 digits (数字) include three parts. Each part has a different meaning. The first three numbers tell you the mobile phone service provider (服务提供商) you are using. For example, 135 is for the China Mobile Communication Corporation (中国移动) and 186 is for China Unicorn (中国联通). The fourth to the seventh digits tell you where the number is from. And the last four digits are random (随机的). 

The main reason for using 11 digits is that we have the largest population (人口) in the world. We once had 10 numbers. But as our population grew, there were not enough numbers for us to use. So we began to use 11 digits from 1999. 

11 digits can make tens of billions of mobile phone numbers. That's enough for each person to have seven or eight phone numbers to use in China. Also, we can reuse the mobile phone numbers. Usually, the service provider will use a canceled number again after three to six months. If you call a number that you haven't called for a long time, you may find its owner has changed. 

Besides China, Britain and Japan also use 11-digit mobile phone numbers. But their numbers always start with 0. So they cannot make as many numbers as we can. Countries like the United States, Australia and India use phone numbers with 10 digits. Canada's mobile phone numbers are perhaps the world's shortest: they use seven digits.