We have always been interested in the moon. 2000 years ago people already knew it moved around the earth and where it would be in the sky at different times of the year. At that time, everything about the moon was learned by watching it carefully in the sky.

    When scientists could use telescopes to study the moon more closely, their ideas began to change. They could see the moon was made of rocks. Most scientists thought moon rocks would be different from those on Earth. This was because they believed the moon had once been a planet that had been caught in the earth's gravity (引力) millions of years earlier.

    In 1969 moon rocks were finally brought to the earth and studied. Much to their surprise, scientists found that, except for water, the moon and the earth were made of the same things. Once again new ideas were needed for this new information.

    After years of study, most scientists now think that the moon was once part of Earth. They believe very early in its history, maybe 4 million years ago, something about the size of Mars hit Earth. This sent billions of rocks into space around our planet. These rocks slowly joined together and after many years became the moon.

    However, in the future, even though our ideas about the moon may change again, we will still be interested in it.

阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

Going Green

Green is no longer just a color. It is a new way of thinking about the world and a way of living your life. It's catching on all over the world. More and more people decide to "go green" because they know that we only have one planet to live on. We won't be able to live on it much longer if we keep wasting energy, and destroying(破坏) our home with air, land, and water pollution.

"Green Living" means:

    Understanding that your choices affect(影响) not just you, but everybody everywhere.

    Understanding that your choices affect not just today, but the future.

Understanding that when we talk about "saving the planet" or "saving the environment," we are actually talking about saving ourselves!

You may be thinking: "Hey, I'm just one person, on a planet with billions. I can't really make a difference." Well, have you ever seen a group of people do "the wave(波浪)"? It always starts off with one or two people, jumping up and down like crazy. Soon thousands of people are joining in. "Going green" is just like that. It starts with small, simple actions. It can soon build into a wave that will change the whole planet and lead us all to healthier, happier lives.

    Many students have already shared with us their efforts to help the environment:

Gabrielle, 12, writes, "I have helped my community plant a garden and I ride my bike or skateboard to school."

Kaitlyn, 10, says, "Lots of paper towels are thrown away, so I use a reusable cloth towel to dry my hands instead."

"I always recycle(重复利用)" says Natalie, 13. "You can call me a recycler! I always look at the bottom of things. I want to see whether they have the little sign that tells you it can be recycled. So I almost recycle everything!"

Now it's your turn to think about how you can "go green". Make important choices and take actions to improve the environment right around you and the health of the whole world.

B

    Have you ever stayed in a hotel? Most Chinese hotels often provide guests with things like disposable (一次性的) toothbrushes, toothpaste, shampoo and slippers. Many guests like the idea because they don't have to bring their own. But, if you travel to Beijing, remember to bring your own things. Starting from June, some hotels in Beijing will no longer provide guests with these disposables. They want to ask people to use less disposable things.

    Many disposable things are made of plastic. People throw them away after only using them once. It is a waste of natural resources (资源) and is very bad for the environment. Do you know, one Chinese person makes as much as 400kg of waste a year! Most of that waste comes from disposable things. In Beijing, people throw away about 19,000 tons of plastic bags and 1,320 tons of plastic lunch bowls every year! Plastic can take between 100 and 400 years to break down. So the less plastic we throw out, the better. So, wherever you travel, bring your own things and use them again and again.

    Back at home and school, you can also do something to make our world a better place. Try to do these things in your daily life: Use cloth shopping bags, not plastic ones. After using a plastic bag, wash it out and let it dry. Then you can use it over and over again. Do not use paper cups. At your school canteen（食堂）, use your own bowl and chopsticks instead of disposable ones.

    A British company has made a new product to help us save money. The product is a wristband that gives us an electric shock if we spend too much money. The wristband is called Pavlok. It is linked to our bank account. It knows how much money we have in the bank. If we go shopping and there is not enough money in our bank account, the wristband makes an electric shock on our wrists. This warns us not to overspend. The company is called Intelligent Environments. It wants to work with banks to help customers with their money. So far, no banks in Britain have said they would ask their customers to wear Pavlok. They could start doing this in the future.

    The Pavlok wristband is part of the Internet of Things. This is the idea that everything in our life will be connected to the Internet. The CEO of Intelligent Environments, David Webber, said people liked the idea of the Pavlok. Shoppers would rather get a small electric shock in the store from the wristband than get a big shock later when they see their bank account. Mr. Webber said the Pavlok would be great for people who cannot stop spending because they have no power or their power is weak. He added that many young people have the "ostrich effect". This is when people put their heads in the sand and buy things rather than look at how much money they have in their bank accounts.