阅读下面材料，从每题所给的三个选项（A、B和C）中，选出最佳选项。

Invention 1	These glasses are made from a special liquid(液体). They allow users to adjust the focus(调整焦距) of the glasses until everything is clear. They are designed for children. So they won't buy new glasses every time when their eyesight changes.
Invention 2	The Donkey Bike has a strong steel bar(钢条) running along it. It can carry both a gas can and a pet at the same time when you ride this bike.
Invention 3	This machine looks friendly and is called Little Printer. It can print news headlines, riddles and other things on a roll(卷) of paper. So you can make your own little newspaper with it.

    The earth is about 4,600 million years old. Modern man has lived on the earth for only 35,000 years, but during that time, we have changed our planet in many ways. Many of the things that we have done are good, but more are not good for the earth.

    Water pollution

    A lot of people, birds and fish die each day because of water pollution. Factories have polluted the land and the water. As a result, many river and lakes are now dead.

    Air pollution

    In big cities, factories, as well as cars, trucks and buses are the biggest cause of air pollution. Many people in cities now have bad health problems. For example, Mexico city used to be a beautiful sunny capital, but today it is almost covered by thick brown clouds.

    Soil pollution

    In order to have a good harvest, most of the farmers use chemicals too much on their fields. That's bad for the soil. But this kind of pollution is difficult to stop.

    Hope for the future

    These problems are very serious for our future, so all of us should do something to improve our environment. If we can stop pollution, our planet will become more and more beautiful and our health will be better. Let's be greener people.

    E-waste is fast becoming a serious problem around the world. This report will examine this problem and provide some possible ways to solve it.

We live in a society that is producing and using electronics(电子产品) all the time. It is often cheaper to buy new products than to repair old ones. Also, through clever advertising, companies always encourage people to change their old TVs, mobile phones and computers for the latest models. E-waste is created when we throw away old ones. In the EU alone, about 8,700,000 tons of e-waste is produced each year. Sadly, just over 1,000,000 tons is recycled.

    Burying(填埋) e-waste or burning it cause serious problems for the environment. Electronics have dangerous things in them. These things can then get into the ground or pollute the air when they are burnt.

    In recent years,   ▲  . However, their plans are not always managed properly. Sometimes electronics are just sent to poor countries such as Ghana. Here they are often burnt in public areas, which is very bad for people's health. Setting up recycling centers is a good way to solve this problem. E-cycling centers could recycle the parts that can be reused and deal with the rest properly.

    Another way is to make producers responsible(负责任) for their used products. This means that producers must take back old products which are no longer wanted. They should then make sure they are properly recycled or reused.

    As for us, we should try to cut down on e-waste. Change electronics only when we have to. And don't buy a product just to have the latest model.

    E-waste is a serious problem in the modern world. Both producers and users must take actions and try to keep it to the smallest amount.

    National parks are large areas of public land. They give a safe home to local plants and animals. They help keep the air and water clean. They also give us the best trips. Today, there are about 7,000 national parks around the world. Forbes has listed 12 of the most beautiful ones in the world that will surprise you with their amazing landscape, geographic wonders and colourful plants and animals.

    The Grand Canyon National Park of the US is one of the natural wonders of the world. It is best known for its size and depth. It is 446 kilometres long, up to 29 kilometres wide, and 1.6 kilometres deep. The immensity of the canyon makes people feel they are very small. Every year, about 5 million people visit here. Taking a tour in the South Rim offers visitors the park's full views, while the North Rim shows beautiful wild flowers

    If you love animals, you'll like the Serengeti National Park in Tanzania. The "Big Five" live here. They are the lion. African elephant, African leopard, rhinoceros and African buffalo. The name "Big Five" came from the five animals that were the hardest to catch. Now they are what people most want to see in the wild. If you visit the park, you should never miss the migration (迁徙) of over 1.5 million wildebeest (牛羚) and 250,000 zebras every year. This is the most famous site of the park.

    Fraser Island is in Queensland, Australia, about 200 kilometers north of Brisbane. It is about 120 kilometers long and 240 kilometers wide. It is a very important island because it is completely made of sand. In fact, it is the largest sand island in the world. There is no airport on the island, but there is a long beach along the east coast. Planes arrive and leave from here.

    The sand makes unusual shapes. There are hills made of sand called sand blows. Nothing grows on them. They move one or two meters a year from the northwest towards the southeast of the island, getting bigger and bigger. At other places on the island, such as Rainbow Gorge, The Cathedrals and Red Canyon, the sandy rocks have different colors. Sometimes the rocks are so brown that they turn the sea brown, like coffee.

    Surprisingly, the sandy island has a lot of different plants and animals. There are dark forests—eucalyptus woods, beautiful flowers and over a hundred lakes. There are many kinds of birds, like owls and curlews. There are many animals there, too, such as crocodiles, flying foxes and wild dogs called dingoes.

    About 500,000 people visit the island every year to see the island's beauty and nature. People enjoy camping and hiking（徒步）there. Unluckily, the visitors create problems. They damage plants and frighten animals. Their sun cream（防晒霜）makes the water dirty. So it is necessary to manage the visitors. For example, people may not use motor boats or go fishing in the lakes, and they need official papers to drive there.

No one knows when the first kite was made. The first record of a kite was more than 2,000 years ago in China. Han Xin, the leader of an army, wanted to bring down a king. He decided to dig a tunnel (隧道)into the king's palace. He flew a kite over the wall of the palace to make sure the length (长度)of its string (线).In this way, he could determine how long the tunnel should be. His men in the tunnel took the kite string with them. When they reached the end of the string, they knew to dig up.

    Kites have been flown in Japan for hundreds of years. In the 1700s, kites were flown in autumn to give thanks for a good harvest. They were also flown to send good wishes to couples who had their first son. Today in Japan, kites are often flown as part of a celebration, such as the beginning of a new year. And kite festivals are held each year in many parts of the country.

    Kites have been used for scientific purposes in the western world. In 1752，Benjamin Franklin tied a key to a kite and flew it in a storm to find out that lightening was a form of electricity. In the 1890s, Lawrence Hargrave invented the box kite to test ideas about flight. From 1898 until 1933, the United States Weather Bureau (气象局) used box kites to collect weather data. The Wright brothers also experimented (试验)with kites. What they learned helped them make the first airplane flight in 1903.