What are they doing for holiday?

    They are happy because they are on holiday.

    Mary is visiting her aunt in Paris. She is very excited to be in Paris. It is a very famous city. And it is a good place to go shopping!

    Tom is fishing in the lake. Because the water is very clean, there are so many fish in the lake. Tom is having a good harvest (收获).

    Simon and Bill are good friends. They are usually very busy with their study every day. So they want to do something different. They are going bike riding together in the beautiful countryside (农村，乡下). It's relaxing.

    Jesse is taking some photos in the park. The park is very beautiful in autumn, and it's a good place to take photos.

    Everyone gets tired sometimes. It's important to have a rest. And it's good for your health. It can help you work or study better, too. I hope everyone is having a good time.

根据短文内容，完成下面表格。

    In the 13th century, the famous Italian traveler, Marco Polo, traveled a long way to China. During his stay in China, he saw many wonderful things. One of the things he discovered was that the Chinese used paper money. In Western countries, people did not use paper money until the 15th century. {#blank#}1{#/blank#}.

    A Chinese man called Cai Lun invented paper almost 2,000years ago. He made it from wood. {#blank#}2{#/blank#} He then put these pieces of paper together and made them into a book.

    {#blank#}3{#/blank#} We use a lot of paper every day. If we keep on wasting so much paper, there will not be any trees left on the earth. Every day, people throw away about 2,800 tons of paper. It takes 17 trees to make one ton of paper. This means that we are cutting nearly 48,000 trees every day.

    Since it takes more than 10 years for a tree to grow, we must start using less paper now. If we don't, we will not have enough time to grow more trees to take the place of those we use for paper.

    {#blank#}4{#/blank#} We can use both sides of every piece of paper, especially when we are making notes. We can choose drinks in bottles instead of those in paper packets. We can also use cotton handkerchiefs and not paper ones. When we go shopping, we can use fewer paper bags. If the shop assistant does give us a paper bag, we can save it and reuse it later.

    {#blank#}5{#/blank#} If we all think carefully, we can help protect trees. But we should do it now, before it is too late.

    On 19th September 1783, Pilatre De Rozier, a scientist, sent the first hot air balloon. The passengers were three animals and the balloon stayed in the air for about 15 minutes before hitting back to the ground.

    The first manned(载人的) flight was about 2 months later, with a balloon made by 2 French brothers. The balloon flew for a period of 20 minutes.

    Sailing through the sky in the balloon, high above buildings and trees, you can't feel or hear the wind because you're traveling in the same direction and at the same speed as it is.

    A hot air balloon has three main parts: the balloon, called an envelope; a basket, where passengers ride; and a burner system, which supplies the hot air.

    Most balloon envelopes are made of strong, lightweight nylon(尼龙). They are different in size and shape, but they have to be really, really big to lift even one person. Most weigh more than an adult man.

    The basket is usually made of wicker(柳条), which is strong but not too hard. It needs to bend a bit for a soft landing, just like a good jumper bends her legs instead of keeping them straight when she lands.

    The hot air balloon works on the theory that hot air rises faster than cooler air. When the burner system is turned on, it makes a noisy sound, but once the balloon is flying, the burner can be turned off. The air in the envelope will then cool, and the balloon will slowly go down unless the pilot starts the burner system again.

    To control a hot air balloon, a pilot adds hot air to it to go up or lets the air out to go down until he finds a wind blowing in the direction he wants to fly. But no matter which way the wind blows, the passengers have an amazing bird's-eye view of the world.