One weekend in May 2015, over 48 centimeters of rain fell in Houston, Texas, USA. Soon the city was covered with water. The rising water rushed into the cars on the roads. There were 16 deaths that weekend.

      Changing Weather

      The weather is changing. Over the last few years, heavy rains have caused floods (洪灾) in Brazil, Pakistan, and Thailand. Droughts (干旱) have struck Russia and Australia. Heat waves have killed thousands in Europe. There are more different kinds of terrible wild weather all over the world. In 2011 alone, the bad weather caused the world to lose 150 billion dollars.　

      Warmer and Wetter

      As more wild weather events happen, a worried world is beginning to ask questions like: What is going on with the weather? And why? Many also want to know: Is this natural, or are we to blame (责怪)?

      The answer seems to be: a little of both. Wild weather is natural.   ▲   This global (全球的) warming makes heat waves more likely to happen. The higher temperatures also cause more water to enter the air. This causes much more rain. Some scientists also believe global warming makes some storms stronger.

      This means we're likely to see more wild weather. “But we don't have to just stand there and take it,” says Scientist Michael Oppenheimer. He and other scientists say we need to stop the Earth from getting warmer. We also need to be prepared, to do things that will help save lives.

    Smartphone apps certainly make our lives easily. However, sometimes they can also cause problems.

    Recently, the Ministry of Education(教育部) announced that teacher should not use Wechat or QQ to give homework or ask parents to grade kids's homework.

    Many teachers in China depend heavily on apps to give homework. The kids have to do their homework, stare at a phone screen. For example, Liu Yanming, a sixth-grade student in Shanghai, usually has to use his mother mobile phone to do his homework. Liu Yong, his father is afraid that apps could distract kids by encourage them to watch something unrelated(无关) to homework. "He is just 12 years old, and I do not want to buy him a cellphone," Liu told China Daily. "I also worry that my son's eyesight will be hurt because of staring at the phone for too long."

    However, Bai Yueping, president of Shanghai Tangzhen Middle School, defended (辩护) using apps for homework. Parents can understand their kids' learning situation and supervise (监督) them to finish the homework, Bai told China Daily.

    Zhang Siqi is a student from Renmin University of China.       "The use of WeChat or QQ to give homework is convenient," Zhang told China Daily. "We're living in an Internet era （时代）. It's unwise to refuse to take advantage of technology."

    Chu Zhaohui, a researcher at the National Institute of Education Sciences, believed that it is impossible to stop the use of electronic devices(设备) in the Internet era. However, students should use them when it's necessary, such as when they do listening exercises. "We don't want to stop outline education models, but they must be used carefully. Modern technologies are good... but they should not steal the show(喧宾夺主) ," he told China Daily.

People often say," Dogs are man's best friend." But cat lovers may not agree. Cats are becoming more popular in China. So, if you want to keep a cat as your pet, here are some things that you should know.

 Cats are great pets if you' re busy. They are great for small homes, because they don't need a lot of space(空间). They are quiet, too. sometimes they meow. Those cute sounds often mean your cat wants food, or it is saying hello.

What do pet cats eat? Those cats usually eat pet food. But in the wild, (野外) cats are carnivores, that means they only eat meat. Cats need more protein than dogs.

When you call your cat's name, it turns its head or does nothing at all. You may think your cat doesn't know its name. In fact, your cat knows its name. But most of the time, it just want to ignore (忽略) you and" be cool".

Cats are great pets if you know more about them. Don't you think so?

Leeks are so common that you have probably never thought much about them. They grow easily in our gardens and don't look very special, but that doesn't mean they are not interesting! Leeks belong to the Allium family of vegetables, which also includes onions. Like onions and other members of the Allium family, leeks are a kind of vegetable with white soft parts and leafy green tops. The bulb(鳞茎), however, is not round, but just slightly larger than the stem nearest the roots. The more rounded the bulb, the older the leek. Leeks are usually about 30 cm long, but they can grow much bigger. Do you know growing leeks can win you a prize? Some gardeners grow big leeks and hold competitions to find the biggest type of leek. The heaviest leek ever weighed more than 8 kg. 

People have been eating leeks for thousands of years. The Ancient Roman Emperor Nero ordered his cooks to serve him leeks every day, as he believed they would improve his singing voice! People in Wales loved leeks so much that they made them their national symbol. As the story goes, about 400 years ago, Welsh soldiers were fighting in a war. They put leeks in their hats so that they could tell their friends from their enemies. 

Leeks are especially loved by cooks all over the world, as they give flavor(味道) to lots of dishes. Leeks taste a bit like onions, but their flavor is much weaker. They taste especially good in soups. In France, a leek and potato soup is eaten cold. Leeks go well with meat. 

So now we know that leeks are delicious, but are they good for you? Yes! Leeks are full of iron(铁). Experts now believe that eating leeks and other members of the Allium family can also help people keep their blood pressure under control and their hearts healthy.