The word“day”has two meanings. When we talk about the number of days in a year, we are using“day”to mean 24 hours. But when we talk about day and night, we are using“day”to mean the time between sunrise and sunset. Since the earth looks like a ball, the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning（旋转）of the earth. At the equator（赤道）day and night are sometimes the same length（长度）. They are each twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6 o’clock in the evening. For six months the North Pole is tilted（倾斜）toward the sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than the Southern Hemisphere. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.
【小题1】A place is moved from day into night and from night into day over and over by ____ of the earth.

根据下列句子及所给单词的首字母写出所缺单词。在填写答卷时，要求写出完整单词。 (每空限填一词)
【小题1】He is very smart．He went to university at the a   of 15．
【小题2】Never cross the street when the traffic lights are r   ．Wait until it’s green．
【小题3】It doesn’t look like rain，so you needn’t b     your umbrella with you．
【小题4】I miss my family and really feel l     without any friends in this new city．
【小题5】Where is my watch?I can’t f     it．

It was very late at night. An old man came to a small town. He found an inn (小旅馆) and Wanted to slay there for the night. After he went to his room, the owner said to his 41   ."Look at hisbag. There must be much money in it. Let’s take it away when he’s 42 , shall we? ’
"Oh, no," said the woman. "He must 43 his bag when he wakes up tomorrow morning. If he can’t find it, he’ll telephone the police."
They thought for a few minutes. Then the woman had an 44 . "We have forgetful grass. Why not put some forgetful grass into his food? If he 45 the food, he will forget lo take his bag away."
The old man ate the food 46 the forgetful grass and went to bed. The next morning when the owner got up, he found the door 47 and the old man had gone away with his bag. He woke his wife up and said to her angrily, "How foolish you are! Your forgetful grass isn’t 48 at all."
"No, I don’t think so. He must forget_49__," his wife said.
"Oh! I remember now! He forgot to 50 for the night," cried out the man suddenly. Then they looked at each other without saying a word.

In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.
Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.
Until now, even the most advanced (先进的) robot was almost certain to break down when it was damaged (毁坏). That is because its computer inside simply doesn’t know how to make the machine work after its shape has changed. 
To deal with this problem, the scientists put eight motors (发动机) and two sensors (传感器) that read how the machine is working. They all give signals to the machine’s software. Using this information, the computer can then figure out the machine’s shape at any moment.
The new technology is a big advance in robot-making, scientists say, and it’s far from scary. It may someday help scientists create better artificial (假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.
“It has been difficult to design robots that can work well when the environment changes or when it’s damaged,” says Olaf Sporns of Indiana University in US. “With this work, we are nearer to solving this problem.”
【小题1】Why do robots easily break down when they are damaged?

What’s your dream vacation? Watching wildlife in Kenya? Boating down the Amazon? Sunbathing in Malaysia? New chances are opening up all the time to visit the world. So we visit travel companies, compare prices, and pay our money.
We know what our vacation costs us. But do we know what it might cost someone else? It’s true that many poorer countries now depend on tourism for foreign income. Unfortunately, though, tourism often harms the local(本地的) people more than it helps them.
It might cost their homes and lands. In Myanmar, 5,200 people were forced to leave their homes among the pagodas(佛塔) in Bagan so that tourists could visit the pagodas.
Tourism might also cost the local people their jobs and dignity(尊严). Local workers often find only low-paying jobs in the tourist industry. And most of the money do not help the local economy（经济）. Instead, money return to the tour operators in richer countries, When the Maasai people in Tanzania were driven from their lands, some moved to poor places of the city. Others now make a little money selling things or acting for photos.
Problems like these were noticed more than 20 years ago. But now tour operators and local governments are working together to begin correcting them. Tourists, too, are putting on the pressure.     
The result is “ethical（合乎职业道德的）tourism”. Ethical tourism has people at its heart. New international agreements and rules can help protect the people’s lands, homes, economies and cultures. The beginnings are small, though, and the problems are complex(复杂的).
But take heart. The good news is that everyone, including us, can play a part to help the local people in the places we visit. Tour operators and companies can help by making sure that local people work in good conditions and earn the money they should get.
They can make it a point to use only locally owned hotel, restaurants and guide services. They can share some money to help the local economy. And they can help the local people plan and manage tourism.
What can tourists do? First, we can ask tour companies to provide information about the conditions of local people. We can then make our choices and tell them why. And while we’re abroad, we can:
Buy local foods and products.
Pay a fair price for goods and services and not bargain for the cheapest price.
Ask before taking photographs of people.
They are not just part of the scenery!
Let’s enjoy our vacation and make sure others do, too.
【小题1】Which of the following is not mentioned?