There are nearly 400 different types of sharks, but only about 30 types have even been reported as attacking human beings.
The chances of being attacked by a shark are very small compared to other dangers. Many more people drown（溺死）in the ocean every year than are bitten by sharks. The low number of attacks that happen every year proves that sharks do not feed on humans if they have the choice. There are three types of shark attacks. The main one is known as a ‘hit and run’. The shark attacks because it thinks you are a fish, but when it tastes a human it decides not to eat you. The second type is called a ‘bump and bite’. The shark bumps you to find out if you are fit to be eaten and then bites you if it thinks you are. The third type is called a ‘sneak’. When attacking in this way, the shark waits for you to swim by and attacks you suddenly. The latter（后者的）two types of attack are more likely to be deadly for humans.
However, your chances of being attacked by a shark can be reduced if you follow the advice below.
Do not swim in the dark. Sharks can still see you but you cannot see them.
Do not swim if you are cut or if you have a fresh wound. Sharks can smell blood over a long distance.
Do not wear bright clothing or jewellery because sharks are attracted to colours and shiny objects.
Try and stay in groups, as sharks usually avoid large numbers of people.
Don’t be frightened（受惊吓）by sharks as there is 30 times greater chance of being hit by lightning than being attacked by a shark.
【小题1】Are there only 30 types of sharks in the world?
【小题2】Are the chances of being attacked by a shark small or big compared to other dangers?
【小题3】What are the two deadly shark attacks called?
【小题4】Why should you try and stay in groups to avoid the shark attack?
【小题5】What does the writer mainly tell us in the passage?

There are nearly 400 different types of sharks, but only about 30 types have even been reported as attacking human beings.
The chances of being attacked by a shark are very small compared to other dangers. Many more people drown（溺死）in the ocean every year than are bitten by sharks. The low number of attacks that happen every year proves that sharks do not feed on humans if they have the choice. There are three types of shark attacks. The main one is known as a ‘hit and run’. The shark attacks because it thinks you are a fish, but when it tastes a human it decides not to eat you. The second type is called a ‘bump and bite’. The shark bumps you to find out if you are fit to be eaten and then bites you if it thinks you are. The third type is called a ‘sneak’. When attacking in this way, the shark waits for you to swim by and attacks you suddenly. The latter（后者的）two types of attack are more likely to be deadly for humans.
However, your chances of being attacked by a shark can be reduced if you follow the advice below.
Do not swim in the dark. Sharks can still see you but you cannot see them.
Do not swim if you are cut or if you have a fresh wound. Sharks can smell blood over a long distance.
Do not wear bright clothing or jewellery because sharks are attracted to colours and shiny objects.
Try and stay in groups, as sharks usually avoid large numbers of people.
Don’t be frightened（受惊吓）by sharks as there is 30 times greater chance of being hit by lightning than being attacked by a shark.

1. 1.

   Are there only 30 types of sharks in the world?

2. 2.

   Are the chances of being attacked by a shark small or big compared to other dangers?

3. 3.

   What are the two deadly shark attacks called?

4. 4.

   Why should you try and stay in groups to avoid the shark attack?

5. 5.

   What does the writer mainly tell us in the passage?

Last week, 169 Junior 1 students at No. 35 Middle School of Shenyang took their first no-teacher exam. After the teacher handed out the exam paper, he left the room and never came back. A student collected in the papers when the exam ended.

“That test was not only a test of knowledge, but also a test of moral(道德). We wanted to show students how important honesty is, ”said Cai Wenguo, the school’s headmaster. The school says no cheating (作弊)happened in the test. Next year, it wants 80％ of its exams to be without teachers. But students have different ideas.

“I was happy and excited during the exam because my teachers trusted me, ”said Lang Yudan, a 13-year-old girl in Class 11.

“Schools must trust students a lot not to use invigilators（监考人）. But I think it is too early. Some students will cheat if there are no invigilators. And the students will not be able to ask for help when needed. ”said Hua Sha.

“I don’t like having invigilators in exams. When they walk around the classroom, they make me nervous. I would get higher marks without them in the room because I would feel more relaxed. ”Liu Qingxi said.

“I think it’s very important to have invigilators in exams. Many students want to check their answers with each other after they have finished papers. And they can also keep the classroom in order when something unusual happens. They may make me nervous, but I still think we need them. ” Shangguan Yuan said.

Not using invigilators may be a good idea. But before using it, schools must tell students the importance of honesty and try to find ways to solve something unusual in exams.

1.The passage mainly talks about ______.

2.No. 35 Middle School of Shenyang held a no-teacher exam to _______.

3.From what the students have said, we know ________.

4.In the sentence “And they can also keep the classroom in order when something unusual happens”“they”refers to _________.

In the summer of 1978 an English man named Steven was driving his tractor through a field of wheat when he discovered something strange. Some of his wheat was lying on the ground. The flattened wheat formed(形成)a circle about six meters across . Around this circle were four smaller circles of flattened wheat.
　 Three years later a farmer who lived nearby discovered almost the same circles in one of his fields. These circles were larger—nearly 15 meters across . That same year , another English farmer discovered three circles of flattened wheat on his land—one large circle between two small circles. During the following years, farmers in England found circles in their fields more and more often.
　 The circles are called “crop circles” because they usually appear in fields of wheat or corn. The wheat in the circles lies on the ground but is never broken; it keeps on growing, and the farmers can later harvest it. Farmers always discover the crop circles in the morning, so the circles probably form at night. They appear only in the months from May to September. What causes the crop circles?
　 At first, people thought that some kids were making them as a joke, or that farmers were making them to attract tourists.(In fact, in 1991, two men said they made the circles themselves, but many scientists don’t believe them.) People tried to copy them: They tried to make circles exactly like the ones the farmers had found. They couldn’t do it. They couldn’t enter a field of wheat without leaving tracks, and they couldn’t flatten the wheat without breaking it.
　 Several times people reported seeing stranger objects near the fields where crop circles later appeared. Many people believe that these crop circles are the messages sent by living things from outer space(外层空间)or the marks left by their spaceships.
　 Scientists who have studied the crop circles try to find out what causes them. In the summer of 1990 some scientists spent three weeks in the part of England where many circles have appeared. They had all the latest high-tech equipment(最新高科技设备). The equipment—worth 1.8 million dollars—got nothing. But one night, as the scientists were watching a field, crop circles formed in the field behind them, which were quite different from the others. The scientists had neither seen nor heard anything.
　 When Steven discovered the crop circles on his land in 1978, he said, “It was just like something that had landed in the field from the air and gone back up again. I don’t know what to make of these things.”
　 Crop circles have appeared in England, Japan, the United States and Russia. Experts from all over the world have studied them, and they say what Steven said: They don’t know what to make of these things.
【小题1】Which picture is probably the one formed in the field behind the scientists?

【小题2】“Flattened wheat” means ___________.