解析：选择。这道题问的是主要原因，一定是该段的主题词，这段主要是在分析铁路托运费用上涨的原因，其中谈到了.变化的交通，.华尔街的支持，都是费用上涨的原因，但.变化的交通，是投资的原因。.华尔街的支持，是贷款的原因，这些次要的原因。而真正的根本原因是.持续的兼并，acquire上下文重复两次。
6.If you feel awkward being humorous, you must practice so that it becomes more natural. Include a few casual and apparently off-the-cuff remarks which you can deliver in a relaxed and unforced manner. Often it's the delivery which causes the audience to smile, so speak slowly and remember that a raised eyebrow or an unbelieving look may help to show that you are making a light-hearted remark.(02年passage 1第4段)
To achieve the desired result, humorous stories should be delivered.
［A］ in well-worded language.
［B］ as awkwardly as possible.
［C］ in exaggerated statements.
［D］ as casually as possible.
解析：选择［D］，这道题问的是幽默故事应该如何被制造。casual----- natural-----light-hearted，
7.What they found, in attempting to model thought, is that the human brain's roughly one hundred billion nerve cells are much more talented—and human perception far more complicated—than previously imagined. They have built robots that can recognize the error of a machine panel by a fraction of a millimeter in a controlled factory environment. But the human mind can glimpse a rapidly changing scene and immediately disregard the 98 percent that is irrelevant, instantaneously focusing on the monkey at the side of a winding forest road or the single suspicious face in a big crowd. The most advanced computer systems on Earth can't approach that kind of ability, and neuroscientists still don't know quite how we do it. (02年passage 2第5段)
The author uses the example of a monkey to argue that robots are.
［A］ expected to copy human brain in internal structure.
［B］ able to perceive abnormalities immediately.
［C］ far less able than human brain in focusing on relevant information.
［D］ best used in a controlled environment.
解析：选择［C］。题干问用猴子的例子证明机器人如何，猴子的例子是为了首句中的观点，观点是人的大脑比机器人更加智慧，"人的大脑” 在反复重复，言外之意就是机器人没有人的大脑智慧。
8.To take advantage of this tool, some impoverished countries will have to get over their outdated anti-colonial prejudices with respect to foreign investment. Countries that still think foreign investment is an invasion of their sovereignty might well study the history of infrastructure (the basic structural foundations of a society) in the United States. When the United States built its industrial infrastructure, it didn't have the capital to do so. And that is why America's Second Wave infrastructure-including roads, harbors, highways, ports and so on-were built with foreign investment. The English, the Germans, the Dutch and the French were investing in Britain's former colony. They financed them. Immigrant Americans built them. Guess who owns them now? The Americans. I believe the same thing would be true in places like Brazil or anywhere else for that matter. The more foreign capital you have helping you build your Third Wave infrastructure, which today is an electronic infrastructure, the better off you're going to be. That doesn't mean lying down and becoming fooled, or letting foreign corporations run uncontrolled. But it does mean recognizing how important they can be in building the energy and telecom infrastructures needed to take full advantage of the Internet.(01年passage 2)
The writer mentioned the case of the United States to justify the policy of _________.
［A］providing financial support overseas
［B］preventing foreign capital's control
［C］building industrial infrastructure
