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.

1.Which picture is probably the one formed in the field behind the scientists?

2.“Flattened wheat” means ___________.

　　   A. broken wheat             B. lying wheat

　　   C. harvested wheat          D. growing wheat

3.The passage is mainly about something ___________ .

A. that is done by living things from outer space

B. that cannot be solved but found all around the world

C. that cannot be made clear or understood

D. that is discovered and copied by the farmers

Different weather makes people feel different.It influences health, intelligence(智力) and feelings.

　　In August, it is very hot and wet in the southern part of the United States.People there have heart trouble and other kinds of health problems during this month.In the Northeast and the Middle West, it is very hot at some times and very cold at other times.People in these states(州) have more heart trouble after the weather changes in February or March.

　  The weather can also influence intelligence.For example, in a 1983 report by scientists, IQ(智商) of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10% lower.The wind can help people have more intelligence.Very hot weather, on the other hand, can make it lower.Students in many schools of the United States often get worse on exams in the hot months of the year (July and August).

　　Weather also has a strong influence on people’s feelings.Winter may be a bad time for thin people.They usually feel cold during these months.They might feel unhappy during cold weather.But fat people may have a hard time in hot summer.At about 18℃, people become stronger.

　Low air pressure(气压) may make people forgetful(健忘).People leave more bags on buses and in shops on low-pressure days.People feel best at a temperature of about 18℃.

Are you feeling sad, tired, forgetful, or unhappy today? It may be the weather’s problem.

根据短文内容，从A、B、C、D四个选项中选择最恰当的答案。

1.What can cause problems on health？

A.Hot and wet weather   B.A strong wind

C.Warm weather   D.Low air pressure

2.A report shows that people may have more intelligence when ______ comes.

A.rain      B.a strong wind       C.very hot weather      D.low air pressure

3.According to(根据) the writer, fat people may feel bad in ______ weather.

A.cold      B.cool        C.warm         D.hot

4.The writer wants to tell us that ______.

A.hot and cold weather influences all people in the same way

B.weather influences people’s behaviour

C.IQ changes when weather changes

D.people feel good on low pressure days

5.Which is the best title(标题) for this passage？

A.Hot Weather Causes Health Problems

B.Different Weather Makes People Feel Bad

C.Weather Influences Feelings

D.Weather Influences Health, Intelligence and Feelings