单选题
Visitors from space may have landed on our planet dozens, even hundreds of times during the long, empty ages while Man was still a dream of the distant future. Indeed, they could have landed on 90 percent of the earth as recently as two or three hundred years ago, and we could never have heard of it. If one searches through old newspapers and local records, one can find many reports of strange incidents that could be interpreted as visits from outer space. A stimulating writer, Charles Fort, has made a collection of UFO sighting in his book! One is tempted to believe them more than any modern reports, for the simple reason that they happened long before anyone had ever thought of space travel. Yet at the same time, one can't take them too seriously, for before scientific education was widespread, even sightings of meteors, comets, auroras, and so on, gave rise to the most incredible stories, as they still do today.
单选题
According to the passage, visitors from space may have landed on the earth ______. A. long before man had dreamed of it B. long before there were human beings C. in the last few hundred years D. after the space age began
【正确答案】
B
【答案解析】根据本段第一句，Visitors from space may have landed on our planet dozens, even hundreds of times during the long, empty ages while Man was still a dream of the distant future作出该项选择。
单选题
According to the passage, which of the following statements is true? A. All observations of UFO's are unreliable. B. Charles Fort sighted a lot of UFO's himself. C. Older civilization may exist on other planets. D. People have seen visitors from other planets everywhere.
【正确答案】
C
【答案解析】根据本段第二句，they could have landed on 90 percent of the earth as recently as two or three hundred years ago，and we could never have heard of it符合题意。选项A中的 unreliable不恰当，选项B中的sighted a lot of UFO’s himself不正确，选项D中的everywhere不恰当。
单选题
If visitors from other planets have actually landed on the earth, one can assume that they came to ______. A. make war B. communicate C. settle down D. explore
【正确答案】
D
【答案解析】根据本段最后一句，Yet at the same time, one can't take them too seriously, for before scientific education was widespread, even sightings of meteors, comets, auroras, and so on, gave rise to the most incredible stories作出该项选择。
单选题
The author implies that the space age has ______. A. weakened the reliability of reported sightings B. increased the number of UFO sightings C. allowed more scientific study of UFO's D. solved the age-old mystery of UFO's
【正确答案】
C
【答案解析】根据本段最后一句，Yet at the same time, one can't take them too seriously, for before scientific education was widespread, even sightings of meteors, comets, auroras, and so on, gave rise to the most incredible stories, as they still do today作出该项选择。
单选题
According to the passage, ______. A. UFO's are only recent observations B. UFO sightings are not new C. UFO's are just comets, and auroras etc. D. UFO's are inventions by people who lack scientific knowledge
【正确答案】
B
【答案解析】根据本段第三句，If one searches through old newspapers and local records, one can find many reports of strange incidents that could be interpreted as visits from outer space作出该项选择。选项A中的only recent observations不恰当，选项C中的just comets， and auroras etc．不正确，选项D中的are inventions by people不恰当。