Who designed the first helicopter (直升机)? Who painted some of the most famous pictures in the world? Who knew more about the human body than most (1)______ of his time? (2)____________

   (3)____________ He lived in Italy around the year 1500, but many of his inventions seem modern to us today. For example, one of his notebooks has drawings of a helicopter. Of course, he couldn't build a helicopter with the things he had. But scientists say that his idea would have worked.

   (4)___________ He was one of the greatest artists of his day. By the time he was twenty years old, he had been called a master (大师) painter, and as he got older he became even more famous. Sometimes he drew a hand ten different ways before he was ready to paint.

   (5)___________ You may know one of his famous works, the (6)______ (smile) woman (7)______ (know) as the Mona Lisa.

    English homework may be boring for many students. {#blank#}1{#/blank#} Our English teacher, Mrs. Lin, asked us to write an English letter to ourselves in the future. Mrs. Lin said she got the idea from Steve Jobs' time capsule (时光胶囊). In 1983, Jobs buried his time capsule. {#blank#}2{#/blank#}That was 30 years later. So what will you write about to your future self? Everyone was surprised and whispered (窃窃私语) about it.

    " {#blank#}3{#/blank#} And write about how you will make your dream come true. Then you can bury the letter and wait for 20 years to open it again," Mrs. Lin told us.

    It was really interesting! {#blank#}4{#/blank#} Some would like to sing songs and become stars. In my letter, I wrote "I hope to be a doctor." I want to cure (治愈) people and I won't ask for much money, just like my dad.  {#blank#}5{#/blank#} For example I would read more books and learn two foreign languages in my twenties.

    Can we realize our dreams? Let's wait and see!

    Don't be too surprised if you see a car going down the road without a driver in Beijing these days. {#blank#}1{#/blank#}Last month, Baidu began to test its self-driving cars on open roads in Beijing.

    {#blank#}2{#/blank#}Since then, companies like Tesla, Uber and Baidu have been working to produce and test their own self-driving cars.

    Self-driving cars are safer than regular cars. {#blank#}3{#/blank#}They can remove the stress of driving and allow disabled or blind people to get around more easily.

    {#blank#}4{#/blank#}In one test, researchers pointed a laser pointer(激光棒) at the car's sensors(传感器) while it was moving. The car mistakenly thought that the laser beam was in its way and slowed down or changed the direction.

    The software that is used to direct the cars may not be safe enough. {#blank#}5{#/blank#}When we use our computers or smartphones, they sometimes crash (崩溃)  without any reason. But if this happened to a self-driving car, the results could be deadly. Improvements to the software could be a solution to this problem.

    The world itself is becoming much smaller by using modern traffic and modern communication means. Life today is much easier than it was hundreds of years ago, but it has brought new problems. One of the biggest problems is pollution. To pollute means to make things dirty.{#blank#}1{#/blank#}We see it, smell it, drink it and even hear it. Man has been polluting the earth. {#blank#}2{#/blank#}Many years ago, the problem was not so serious because there were not so many people. When the land was used up or the river was dirty in one place, man moved to an-other place. But this is no longer true. Man is now slowly polluting the whole world. Air pollution is still the most serious. {#blank#}3{#/blank#}Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us angry more easily.

    {#blank#}4{#/blank#}They stop people from burning coal in houses and factories in the city, and from putting dirty smoke into the air. Pollution by SO, is now the most dangerous kind of air pollution. It is caused by heavy traffic. We are sure that if there are fewer people driving, there will be less air pollution. The earth is our home. We must take care of it. {#blank#}5{#/blank#}And we must take care of the rise in pollution at the same time.

    In the eyes of many foreigners, Chinese are the best hosts and the worst guests in the world. They're not really bad guests, but because the guest-host relationship in China is much different than in some western counties, it appears they are not nice guests. {#blank#}1{#/blank#}

    {#blank#}2{#/blank#} Whenever I enter a Chinese person's home, there is always fruit on the table for me, and someone is quick to bring me a cup of tea or water. In the west, generally the guest is not a god. {#blank#}3{#/blank#}

    My wife's mother, a very kind elderly Chinese lady, doesn't smoke. When I see some of her guests smoking in her house, as a non-smoker, I feel unhappy. Usually I want to stop them directly, but I must realize that in China, to be a good host, she must not do that. In most North America homes, if you are a guest, and the hosts are not smokers, you should not smoke in their house.  {#blank#}4{#/blank#} But, don't be surprised if they say," No, you can't smoke. "

    {#blank#}5{#/blank#} Some western people may not adapt to these habits very soon. Thankfully my wife is Chinese, so whenever we visit a Chinese family she tells me to buy them a gift. However, giving a gift to a host is not always necessary in my country. So, if you invite international guests to your home, don't be too surprised if they don't bring you a gift.

    In China, you probably won't need to change the guest-host relationship very much because you will probably only be the host, and Chinese are naturally very good hosts. If western hosts invite you to their house, try not to be too surprised if their style of treating you is not what you have expected.

A. In China, guests are almost like gods.

B. Guests in China also have special habits.

C. At the very least, you could ask, "Is it OK if I smoke?"

D. Acting according to the host's way of doing things is usual behavior for a guest.

E. And western guests sometimes look impolite or even rude in the eyes of Chinese guests.