【推荐1】I’m Leo. There is a great artist in my family. She is Lisa. Lisa likes painting a lot. Here are her three paintings.

There is an animal in the first painting. It has two big eyes, a big mouth and two small ears. It has long arms and long legs. It is black and white. There are some apples in its hands. It looks very happy. What is it? I don’t know, but Lisa says it is a panda.

There is a woman in the second painting. She is thin. She has straight blonde hair, a small mouth, a big nose and two big eyes. She looks angry (生气的). Who is she? Lisa says she is our mom. But Mom has curly blonde hair, small eyes and a small nose.

There is an animal in the third painting, too. Its head is an apple. Its hair and tail (尾巴) are leaves (树叶). It has a long mouth, and it is a banana. Its two legs are carrots. What is it? Lisa says it is a horse, but it doesn’t look like a horse.

Lisa is really a great artist, isn’t she?

【推荐2】Animals grow up in different ways. Some newborn animals are helpless but their mothers protect them.

A newborn kangaroo is very small. It is only a few centimeters long. It closes its eyes and doesn’t have hair. It stays safe in its mother’s pouch（育儿袋） for a long time.

A newborn monkey cannot walk. Its mother carries it everywhere. Other baby animals can walk soon after they’re born. They learn to run with their mothers when danger is near. A baby zebra can run, an hour after it is born.

Some baby animals are born in a safe place. Baby wolves are usually born in big holes with little light. Other baby animals are born in the open. A baby elephant is often born on open land.

Animals that drink their mothers’ milk are called mammals（哺乳动物）. A mother bear’s milk is rich. Baby bears have milk for a few months. This is the same with baby zebras. As baby animals grow, they need solid（固体的）food. Baby lions eat what their mother can catch.

【推荐1】From deserts and beaches to playgrounds, sand is a common sight. But you might not know that sand is also a useful resource(资源).

Sand is the second most-used resource in the world after water, the BBC reported. However, the UN said that sand is not limitless(无限的) and that we might be running out of it.

Sand is made up of very small pieces of rock, soil and minerals(矿物质). It can take tens of thousands of years to form. But now we are using sand more quickly than it is being formed. According to the BBC, we use about 15 billion tons of sand every year to build houses, roads and other things. That’s enough to build a 20-metre-high by 20-metre-wide wall around the equator(赤道) every year.

People also put sand in the sea to make new islands. Singapore, for example, is now 20 per cent bigger than it was in 1965. Palm Islands in Dubai(迪拜) took 94 million cubic metres of sand to build.

If people keep using this much sand, it will run out in many places. Since people need so much sand, they are trying to mine(开采) more of it. But this is bad for the environment. Mining sand may cause beaches to disappear and more floods to happen in places close to the sea. Also, this may affect the habitats of many plants and animals.

【推荐2】Sleepwalking is when your child gets out of bed and walks around as if he’s awake, but he’s actually asleep. Sleepwalking (梦游) doesn’t hurt your child, and it usually disappears when the kid grows up.

Sleepwalking happens during deep sleep. Your child might get out of bed and walk around as if he’s awake, but he won’t respond normally to you or anything around him. This may make you sad. But try not to worry—your child is OK.

In fact, sleepwalking is quite common. 7% to 15% of children sleepwalk, and it doesn’t usually mean that there’s anything wrong with them. Children aged 4 to 12 are more likely to sleepwalk. Both boys and girls sleepwalk.

Sleepwalking often happens in the first few hours of the night. When it happens, your child’s mind is asleep. However, his body is awake at the same time.

Sleepwalking usually has something to do with age and development. However, some things can increase (增加) your child’s sleepwalking. For example:

If your child is sleepwalking at least once every night, it’s best to see a doctor.   Also see a doctor if your child’s sleepwalking is influencing the sleep of other family members, or if you’re worried your child might hurt himself while sleepwalking.

【推荐3】Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins “Twinkle, twinkle, little star” or remember the story of Cinderella or Goldilocks and the Three Bears.

One explanation is the law of overlearning, which can be stated as follows：Once we have learned something, additional learning trials（尝试）increase the length of time we will remember it.

In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as “Twinkle, little star” and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

The multiplication tables（乘法口诀表）are an exception to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.

The law of overlearning explains why cramming（突击学习）for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one’s future development.

【推荐1】Hundreds of years ago, life was harder than it is today. People didn’t have modern machines. There was no modern medicine, either.

Life today has brought new problems. One of the biggest is pollution. Water pollution has made our rivers and lakes dirty. It kills our fish and pollutes our drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution is the most serious kind of pollution to all living things in the world.

Cars, planes and factories all pollute our air every day. Sometimes the polluted air is so thick that it is like a quilt (被状物) over a city. This kind of quilt is called smog.

Many countries are making rules to fight pollution. Factories must now clean their water before it is thrown away, and they mustn’t let dirty smoke go into the air.

We need to do many other things. We can put waste things in the dustbin (垃圾箱) and do not throw them on the ground. We can go to work by bus with our friends in the same car. If there are fewer people driving, there will be less pollution.

Rules are not enough. Every person must help to fight pollution.

【推荐2】Many years ago, Lake Ponkapog in Hartwell, New Jersey, was full of life. Many birds and animals lived beside the water, which was full of fish. Now there are few birds, animals, and fish. The lake water is polluted. It is in a colour of dirty（脏的）brown, and it is filled with strange plants.

How did this happen? First, we must think about how water gets into Lake Ponkapog. When it rains, water comes into the lake from all around. In the past, there were forests all around Lake Ponkapog, so the rainwater was clean.

Now there are many homes around the lake. People often use chemicals（化学品）in their gardens. They use other chemicals inside their houses for cleaning or killing insects（昆虫）. There are also many businesses. Businesses use chemicals in their machines or shops. Other chemicals fall onto the ground from cars or trucks. When it rains, the rainwater picks up all the chemicals from homes and businesses and then carries them into the lake. They pollute the water and kill the animals.

Boats on the lake are also a problem. Lake Ponkapog is a popular place for motorboats. But oil and gas（汽油） from boats get into the lake. So more bad chemicals go into the water this way.

People in Hartwell are worried. They love their lake and want to save it. Will it be possible? A clean lake must have clean rainwater going into it. Clean rainwater is possible only if people are more careful about chemicals at home and at work. They must also be more careful about gas and oil and other chemicals on the ground. And they mustn’t use motorboats any more on the lake. All these may change people’s lives. Only then can Lake Ponkapog be a beautiful, clean lake again.

Pollution of the Earth

The Earth is about 4,600 million years old. People live on Earth for only millions of years.     1     Some things we do are good, but some are not good for the Earth.

    2     That’s because factories pollute the water. As a result, the water in many rivers and lakes is now very dirty.

In big cities, factories, cars and buses are the main causes (原因) of air pollution.     3     For example, Mexico City used to be a beautiful sunny capital, but today there is heavy haze (雾霾) in the sky. So many people get ill because of the polluted air.

In order to have a better harvest (收成), some of the farmers use too many chemicals (化学制品) in their fields.     4    

These problems are very serious.     5     If we can stop pollutions, our Earth will become more and more beautiful.