阅读理解
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 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. In the 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
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
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. ),and they couldn't flatten the wheat without breaking it.
For several times,people reported seeing strange objects near the fields where crop circles later appeared. Many people believe that these crop circles are the messages sent by living things for outer space 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,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:we don't know what to make of these things.