Black death that drove Newton from his college and into a momentous discovery,【C1】______En

Black death that drove Newton from his college and into a momentous discovery,【C1】______ England in 1665. Astronomical records of the time show that 【C2】______ was a year of intense sun-spot activity, and studies of annual tree 【C3】______ , which are wider when the sun is disturbed,【C4】______ that the terrible plague of 1348 was【C5】______ accompanied by an. active sun.

This sounds incredible,【C6】______ we now have evidence that the sun has a direct effect on some of our body【C7】______ . Over 120 ,000 tests made on people in a Black Sea 【C8】______ to measure the number of lymphocytes in their blood. These small cells normally【C9】______ between 20 and 25 percent of man's white blood cells, but in years of great solar activity this【C10】______ decreases. There was a big drop during the sunspot years of 1986 and 1987, and number of people【C11】______ from diseases caused by a lymphocyte deficiency【C12】______ doubled during the tremendous solar explosion of February 1986.

Many of the body's 【C13】______ seem to be influenced by sun-induced changes in the earth's magnetic 【C14】______ If this is so, one【C15】______ to find that the nervous system, which depends on electrical stimuli, would be the most【C16】______ . A study of 5 580 coal-mine accidents【C17】______ the Ruhr river shows that most occurred on the day following solar activity. Studies of traffic accidents in Russia and in Germany show that these increase, by as much as four【C18】______ the average, on days after the【C19】______ of a solar flare. This suggests that accidents may be【C20】______ a disturbance deeper than a simple decrease in reaction time. These results make it clear that man is, among other things, a remarkably sensitive living sundial.

【C1】

A．blanketed

B．swept

C．covered

D．spread