【正文】 s(B) of fertile topsoil that could(C) produce good crops washed(D) away by rains. 40. Since the(A) 195039。 語言培訓(xùn) 資料下載 1 托?？荚嚹M題 1. _________ a major role in future plaary exploration. A． Robots will surely play (B)Robots, which will surely play (C)Because robots will surely be playing D． Surely robots, which will be playing 2. Unlike the owl, bats cannot see very well, but they do have_________. A． it hears very well (B)very good to hear (C)tearing very well D． very good hearing few clues in the United Slates have peting newspapers today, a major change from 1900 _________ more than two newspapers. A． because then most large cities having (B)when did most large cities have (C)then most large cities that had D． when most large cities had hazel extract, _________ distilled from the bark and twigs of the witch hazel shrub, has been utilized in medicine. A． is B． when to be (C)which is D． has been 5. _________ touching in O. Henry’s stories is the gal lantry with which ordinary people struggle to maintain their dignity. A． Most is B． It mostly is C． Is it most D． What is most 6. The face of the Moon is changed by collisions with meteoroids, _________ new craters to appear. A． cause B． causing C． caused D． have cause 7. Social scientists believe that _________ from sounds such as grunts and barks made by early ancestors of human beings. A． the very slow development of language B． language developed very slowly C． language which, was very slow to develop 語言培訓(xùn) 資料下載 2 D． language, very slowly developing 8. _________ substances include various forms of silica, pumice, and emery. A． Natural abrasives occur B． Abrasion occurs in natural C． Naturally occurring abrasive D． A natural occurrence of abrasion 9. _________ in the upper part of their long1 thin legs all9w deer to run swiftly and jump far. A． Muscles are powerful B． There are powerful muscles C． The powerful muscles that D． Powerful muscles 10. Geophysicists have collaborated with archaeologists and anthropologists to study the magic properties of pottery and fireplaces at sites _________ by early humans. A． occupied B． occupying C． which occupy D． were occupied 11. _________ technically proficient。s, folk39。 they consist of rapidly moving particles of numerous different kinds). It doesn39。 in line 7? (A)As part of a list of things containing helium (B) As an example of an unsolved astronomical puzzle (C) To explain how the universe began (D) To explain the abundance of hydrogen in the universe 語言培訓(xùn) 資料下載 23 16. The word vary in line 10 is closest ill meaning to (A) mean (B) stretch (C) change (D) include 17. The creation of helium within stars (A) cannot be measured (B) produces energy (C) produces hydrogen as a byproduct (D) causes helium to be much more abundant In old stars than In young star: 18. The word calculated in line 15 is closest in meaning to (A) ignored (B) converted (C) increased (D) determined 19. Most of the helium in the universe was formed (A) in interstellar space (B) in a very short time (C) during the first minute of the universe39。 In others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same. 語言培訓(xùn) 資料下載 22 Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to he significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.. However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the oneminute point that helium could exist. By this time, the univ erse had cooled sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formation of helium went on for only a relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased. 12. what does the passage mainly explain? (A)How stars produce energy (B)The difference between helium and hydrogen (C)When most of the helium in the universe was formed (D)Why hydrogen is abundant 13. According to the passage, helium is (A) the secondmost abundant element in the universe (B) difficult to detect (C) the oldest element in the universe (D) the most prevalent element in quasars 14. The word constituents in line 7 is closest in meaning to (A) relatives (B) causes (C)ponents (D) targets 15. Why does the author mention cosmic rays39。 autumn could be ushered in by severe frost. For good measure, du ring the spring and summer, drought, heat, hail, grasshoppers, and other frustrations might await the wary grower. Under such conditions, Mandan women had to grow maize capable of weathering adversity. They began as early as it appeared feasible to do so in the spring. clearing the land, using fire to clear stubble from the fields and then planting. From this point until the first green corn could be harvested, the crop required labor and vigilance. Harvesting proceeded in two stages. In August the Mandans picked a smaller amount of the crop before it had matured full