单选题Before microbes were discovered it was believed that some diseases were caused by

单选题______does not belong to The Great Lakes. A. Superior B. Michigan C. Huron D. Walden Pond

单选题I have settled the question of ______ it is necessary for him to drop out of school. A. if B. where C. why D. whether

单选题Satellite photos shows that the clouds are absent or scattered over deforested areas and this could be supported by the following evidences EXCEPT for ______.

单选题This text indicates that the basic component of scientific research is ______.

单选题When Davison was hiding by the stairs, the policemen were

单选题My father was, I am sure, intended by nature to be a cheerful kindly man. Until be was thirty-four years old he worked as a farmhand for a man named Thomas Butterworth whose place lay near the town of Bidwell, Ohio. He had a horse of his own, and on Saturday evenings drove into town to spend a few hours in social intercourse with other farmhands. In town he drank several glasses of beer and stood about in Ben Head's saloon—crowded on Saturday evening with visiting farmhands. Songs were sung and glasses thumped on the bar. At ten o'clock father drove home along a lonely country road, made his horse comfortable for the night, and himself went to bed, quite happy in his position in life. He had at that time no notion of trying to rise in the world. It was in the spring of his thirty-fifth year that father married my mother, then a country school teacher, and in the following spring I came wriggling and crying into the world. Something happened to the two people. They became ambitious. The American idea of getting up in the world took possession of them. It may have been that mother was responsible. Being a school teacher, she had no doubt read books and magazines. She had, I presume, read of how Garfield, Lincoln, and other Americans rose from poverty to fame and greatness, and as I lay beside her—in the days of her lying-in—she may have dreamed that I would someday rule men and cities. At any rate she induced father to give up his place as farmhand, sell his horse, and embark on an independent enterprise of his own. She was a tall silent woman with a long nose and troubled gray eyes. For herself she wanted nothing. For father and me she was incurably ambitious.

单选题The author can’t remember his relatives clearly because ______.

单选题Computers are now being pushed into schools. We're told that multimedia will make (1) easy and fun. Students will happily learn from (2) characters while taught by expertly (3) software. Who needs teachers when you've got (4) education? Bah. These expensive toys are difficult to use in the classrooms and (5) extensive teacher training. Sure, kids love video games (6) think of your own experience: can you (7) even one educational filmstrip of decades past? I'll (8) you remember the two or three great teachers who made a (9) in your life. Then there's cyber business. We're promised (10) catalog shopping just point and click for great deals. We'll order airline tickets (11) the network, make restaurant reservations and negotiate sales (12) . Stores will become obsolete. So how come my local mall does more (13) in an afternoon than the entire Internet (14) in a month? Even if there were a trustworthy way to (15) money over the Internet — which there isn't — the network is (16) a most essential ingredient of trade and commerce: salespeople. What's absent from this electronic wonderland? Human contact. Computers and networks (17) us from one another. A network chat line is a limp (18) for. meeting friends over coffee. No interactive multimedia display comes (19) to the excitement of a (20) concert. As it is, this virtual reality where frustration is legion and where — in the holy names of Education and Progress — important aspects of human interactions are relentlessly devalued.

单选题{{B}}Passage 1{{/B}} Humans are forever forgetting that they can' t control nature. Exactly 20 years ago, a Time magazine cover story announced that scientists are on the verge of being able to predict the time, place and even the size of earthquakes. "The people of quake-ravaged Kobe learned last week how wrong that assertion was." None of the methods conceived two decades ago has yet to discover a uniform warning signal that preceded all quakes, let alone any sign that would tell whether the coming tremor is mild or a killer. Earthquake formation can be triggered by many factors, says Hiroo Kanamori, a seismologist at the California Institute of Technology. So, finding one all-purpose warning sign is impossible. One reason: Quakes start deep in the earth, so scientists can' t study them directly. If a quake precursor were found, it would still be impossible to warn humans in advance of all dangerous quakes. Places like Japan and California are riddled with hundreds, if not thousands, of minor faults. Prediction would be less important if scientists could easily build structures to withstand tremors. While seismic engineering has improved dramatically in the past 10 to 15 years, every new quake reveals unexpected weaknesses in "quake-resistant" structures, says Terry Tullis, a geophysicist at Brown University. In Kobe, for example, a highway that opened only last year was damaged. In the Northridge earthquake, on the other hand, well-built structures generally did not collapse. A recent report in science adds yet more anxiety about life on the faulty lines. Researchers ran computer simulations to see how quake-resistant buildings would fare in a moderate-size tremor, taking into account that much of a quakes energy travels in a large "pulse" of focused shaking. The results: Both steel-frame buildings and buildings that sit on insulating rubber pads suffered severe damage. More research will help experts design stronger structures and possibly find quake precursors. But it is still a certainty that the next earthquakes will prove once again that every fault cannot be monitored and every highway cannot be completely quake-proofed.

单选题______! You should take this chance to attend it. A. How important meeting is it B. How an important meeting it is C. What an important meeting is it D. What an important meeting it is

单选题The word "aberrations" in paragraph 4 is closest in meaning to which of the following words?