雅思阅读第083套P2-Crop circles

Crop circles

The crop circle phenomenon has puzzled and mystified humanity for many years. The designs just appear, placed carefully in fields of food grains. Some are larger than football fields and highly complex in design and construction. Others are smaller and more primitive. We call them crop circles, but many of them are not circular. Some are elongated abstract designs, a few resemble insects or other known forms, and some are mixtures of lines, circles, and other shapes melded into intricate patterns. Most become visible overnight, though it has been claimed that a few have appeared within a half-hour in broad daylight.

Crop circles have appeared all over the world. About 10,000 instances from various countries have been reported in recent years. The first modern rash of crop circles appeared in Australia in December of 1973. A strange circular imprint appeared in a wheat field near Wokurna, a community southeast of Adelaide. Soon seven swirled circles up to 14 feet in diameter appeared in an oatfield nearby. In December of 1989, an amazing set of circles, ranging from a few inches to a few feet in diameter appeared in the wheat best west of Melbourne. As many as 90 crop circles were found. The best documented and largest modern spread of crop circles began in southern England during the summer of 1980. By the end of 1988, 112 new circles had been formed. At that time circles were being reported worldwide, 305 by the end of 1989. The total grew to an outstanding 1,000 newly -formed circles in 1990. In 1991,200 to 300 circles were reported. Crop circles have been documented in over 30 countries, including Canada, the former Soviet Union Japan and the United States.

Nine out of ten circles remained simple with broken stems flattened to the ground and swirled. The stalks around the circles remained completely erect. But over the years, crop circles have become much more geometrically intricate. Patterns involved multiple circles, bars, triangles, rings and spurs. Pictorial imagery also appeared. Reliable eyewitnesses have reported seeing unusual lights and hearing unidentifiable sounds while on an early-morning walk in the countryside where a crop circle showed later that day. High-pitched, warbling, noises have been recorded at the site of some crop circles. On several occasions a strange glow or a darker colouring has been seen in the sky over a crop circle. And in more than one instance, the electrical power of small planes flying overhead has been cut off abruptly. While the causal energies do not seem to harm animals, or even insects as far as we can tell, wild creatures tend to avoid the circles. Flocks of birds have been seen to split apart and fly around the perimeter rather than go directly over a crop circle formation.

Researchers have spent a great deal of time investigating different aspects of crop circles. They try to detect traces of human involvement in the circle-making, test the area of the circle itself for geophysical anomalies, and analyze the field’s grain both from within and outside the circles, searching for differences.

Dr. W. C. Levengood of BLT Research in Cambridge, Massachusetts, has analyzed many grain samples and confirmed, time after time, significant changes at the cellular level of crop circle plants. The plants front the circles have elongated cells and blown-out growth nodes. Seeds front the circle plants often show accelerated growth rates when they are sown, and in some instances, quite different-looking plants result. In many instances it appears that a vortex-like energy causes the plants to swirl down, flattening the design into the land. Whatever this energy is, it does not generally inhibit the plants’ growth. They continue to show normal response to the sun, raising upward over several days following the appearance of the circle. Michael Chorost of Duke University found occasions of short-lived radionuclides in the top layer of soil in some of the formations. A British government laboratory found diminished nitrogen and decreased nematode populations as well as decreased water con-lent in the soil of a formation. Researchers have discovered other anomalies as well, such us curious embedded magnetic particles and charred tissue. Some of the plant stalks within the circles show evidence of being exposed lo rapid microwave heating.

Scientists have attempted to explain crop circles as a result of natural processes. One popular theory accepted by many mainstream scientists and academics, is known as ‘Plasma Vortex Theory’. Developed by Dr. Terence Mearden, it theorizes that electrified air (plasma), on the side of hills, becomes mini-tornadoes and screws down onto the ground, creating the circles. The theory also holds that the electrified air would cause a light to appear above the circle and therefore account for UFO sightings. Although this theory still has considerable support, it has come under lire because of the highly intricate and complex crop circle patterns that have appeared since 1991. Another theory is that the circles are all hoaxes or practical jokes. Major support came to this theory when, on September 9, 1991, two Englishmen claimed to have created approximately 250 crop circles. However, those circles were more rugged than others, and many were already suspect. It is irrational to believe that all crop circles are fake for publicity or other reasons. Many crop circles appeared long be-fore the phenomenon pained large recognition from the public and press. Too many circles and patterns are formed each year in too many countries for them to have been hoaxes. Many crop circles show strange mathematical trails when analyzed.

The crop circle phenomenon is an enigma. Many dollars have been spent by re-searchers and their associations in an attempt to find a solution to this intriguing puzzle which will continue to haunt humanity until an explanation is found

SECTION 2: QUESTIONS 15-27

Questions 15-19

Do the following statements reflect the claims of the writer of this passage?

Write:

YES	if the statement agrees with the views of the writer
NO	if the statement contradicts the views of the writer
NOT GIVEN	if it is impossible to say what the writer thinks about this

15 _________________ Crop circles only appear in wheat fields.

16 _________________ Crop circles have never been documented in tropical countries.

17 _________________ The largest number of crop circle reportings in a single year occurred in 1990.

18 _________________ The patterns of crop circles have become increasingly complex over the years.

19 _________________ All crop circles are hoaxes.

Questions 20-23

Complete the summary below.

Choose NO MORE THAN THREE WORDS from the passage for each answer.

Since the early 1970s, over ten thousand crop circles have been reported around the world, the greatest number in 20_________________ , where in a single year, over one hundred circles appeared. Phenomena such as the appearance of strange lights and unusual 21 _________________ sometimes occur around the sites of crop circles.

22 _________________ are not affected but it has been observed that birds 23 _________________ flying over a formation.