单选题Behavior problems of dogs are believed to ___________.

单选题If a customer buys something that does not meet his expectation, what is the advantage of dealing through electronic commerce over the present normal one?

单选题Forests can provide beauty and prevent ______ . Therefore, we should spare no efforts to protect forests.

单选题While most armies in the world shun their use, and military authorities exclude them from warfare, the technology to produce biological and chemical weapons is widely available around the world. (67) , these weapons are cheap, easy to conceal, and very (68) . Since September 11, 2001, biological weapons (69) to have become the weapon of choice among the desperate (70) of the world. Some people are worried chemical warfare may (71) , which would bring an unbelievable disaster to the whole world. Chemical weapons are (72) in variety. Their effectiveness can be (73) by several factors, including age, (74) , weather conditions, and choice of dissemination. They include nerve agents, blister agents, and choking agents, all of (75) can be ingested through the eyes, lungs, or skin. Satin, a type of nerve gas, was used (76) the Aum Shinrikyo cult in March 1995, killing 12 people and (77) more than 5,500 on a Tokyo subway. Biological weapons, by (78) , are any infectious agent, such as a bacterium or virus, used deliberately to (79) harm on soldiers and civilians alike. This (80) can include toxin and poison derived biologically. Biological weapons can be produced nearly (81) , from government labs to suburban kitchens. Experts contend, however, that the (82) of a deadly virus or bacterium into an effective weapon is anything (83) straightforward: A conventional bomb would likely destroy the germ as it (84) . In contrast, dissemination (85) alternative methods, such as surface mail, has recently (86) quite effective.

单选题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-ruined Kobe learned last week how wrong that assertion was. None of the methods praised two decades ago have succeeded. Even now, scientists have yet to discover a uniform warning signal that precedes all quakes, let alone any sign that would tell whether the coming quake is mild or killer. Earthquake formation can be triggered by many factors, says Hiroo Kanamori, a seismologist (地震学家) at the California Institute of Technology. So, finding one all-purpose warning sign is impossible. One reason: Quakes start deep in the earth, so scientist can't study them directly. If a quake precursor (预兆) were found, it would still be impossible to warn humans in advance of all dangerous quakes. Places like Japan and California are filled with hundreds, if not thousands, of minor faults. It is impossible to place monitoring instruments on all of them. And these inconspicuous sites can be just as deadly as their better-known cousins like the San Andreas. Both the Kobe and the 1994 Northridge quakes occurred on small faults. Prediction would be less important if scientists could easily build structures to withstand every new quake reveals unexpected weaknesses in "quake-resistant" structure, says Terry Tullis, a geophysical 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. But engineers have since found hidden problems in 120 steel-frame buildings that survived. Such structures are supposed to sway with the earth rather than crumple (崩溃). They may have swayed, but the quake also unexpectedly weakened the joints in their steel skeletons. If the shaking had been longer ore stronger, the buildings might have collapsed. A recent report in Science adds yet more anxiety about life on the fault lines. Researchers can computer simulations to see how quake-resistant buildings would fare in a moderate-size tremor, taking into account that much of a quake's 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 pressures. But it is still a certainty that the next earthquake will prove once again that every fault cannot be monitored and every highway cannot be completely quake-proofed.

单选题{{B}}Passage One Questions 26 to 28 are based on the passage you have just heard.{{/B}}

单选题The comic play ______ the audience while tragedy upsets the audience.

单选题Engineering students are supposed to be examples of practicality and rationality, but when it comes to my college education I am an idealist and a fool. In high school I wanted to be an electrical engineer and, of course, any sensible student with my aims would have chosen a college with a large engineering department, famous reputation and lots of good labs and research equipment. But that's not what I did. I chose to study engineering at a small liberal-arts (文科) university that doesn't even offer a major in electrical engineering. Obviously, this was not a practical choice; I came here for more noble reasons. I wanted a broad education that would provide me with flexibility and a value system to guide me in my career. I wanted to open my eyes and expand my vision by interacting with people who weren't studying science or engineering. My parents, teachers and other adults praised me for such a sensible choice. They told me I was wise and mature beyond my 18 years, and I believed them. I headed off to college sure I was going to have an advantage over those students who went to big engineering "factories" where they didn't care if you had values or were flexible. I was going to be a complete engineer, technical genius and sensitive humanist (人文学者) all in one. Now I'm not so sure. Somewhere along the way my noble ideals crashed into reality, as all noble ideals eventually do. After three years of struggling to balance math, physics and engineering courses with liberal-arts courses, I have learned there are reasons why few engineering students try to reconcile (协调) engineering with liberal-arts courses in college. The reality that has blocked my path to becoming the typical successful student is that engineering and the liberal arts simply don't mix as easily as I assumed in high school. Individually they shape a person in very different ways; together they threaten to confuse. The struggle to reconcile the two fields of study is difficult.

单选题Fresh air is ____________ to good health. So you should go out more and take more fresh air.

单选题We may infer that "iodine, fluoride and calcium" are______.

单选题

单选题A.Herefusestodriveher.B.Hehasn'tgotacaratthemoment.C.Hehasn'tgothisdriver'slicenseyet.D.Heisgladtogiveheraride.

单选题[此试题无题干]

单选题Passage One Questions 26 to 29 are based on the passage you have just heard.

单选题A.Asonandtwodaughters.B.Twosonsandtwodaughters.C.Twosonsandadaughter.D.Asonandthreedaughters.