题目内容
听力原文： The use of illegal drugs by U.S. teenagers has increased in the past two years, according to the latest survey by University of Michigan researchers. The increase reverses a downward trend in drug use among teenagers that began in the late 1970s.
Results of a survey of 50,000 eighth, tenth and twelfth graders throughout the United States indicated a sharp rise in the use of drugs. The researchers also noted an increase in the percentage of students who smoke cigarettes, a drop in the percentage of students who drink alcohol, and no change in cocaine use, which remained at a low level.
Although the general rise in the use of drugs is disturbing, the numbers are still far below the recorded high level of drug use in the 1970s.
A consistent drop in drug use, such as the one that occurred be- fore the recent rise, can't be taken for granted, because each generation of American youth has almost no knowledge of drugs and has to learn the same hard lessons.
(26)
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Task 2
Directions: This task is the same as Task 1. The 5 questions or unfinished statements are numbered 41 through 45.
Online services are managed by a host system that maintains a base of information available to satellite users. Users of so-called "dumb" terminals (i.e.those without processing capability) simply access the information base via programs stored on the system. Personal computer (PC) users typically access the host through a modem(调制解调器). A PC software program serves as an interface (接口) between the server and a PC, allowing the user to operate through the online system and select different databases using a keyboard or a mouse.
National and regional online systems usually have local telephone numbers that PC modems can call to access either a local information base or an indirect long-distance connection, thus reducing long-distance telephone fees. Some online systems allow users to copy large volumes of information onto a local memory storage device, which also reduces the time the user is connected to the online system.
Besides offering a great number of different information bases, ranging from full-text journal libraries to reports of missing children, online services allow users to, for example, reserve airline tickets, buy stocks, purchase goods, and communicate with other users. In exchange for the service, users usually pay a monthly membership fee. They may also pay to connect to various databases on the service or to download information.
Online services work by providing users with ______.
采用复式记账法，要求对每一笔经纪业务都要在两个或两个以上相互联系的账户中以相等的金额进行登记。
听力原文：W: Hello？
M: Hi, Mary, this is Bill Johnson.
W: Oh hi, Bill. You weren't in engineering class today, were you？
M: I have the flu. I was wondering if you could tell me what went on.
W: Actually we had an interesting class. Dr. Kelvin talked about a new type of fuel.
M: Oh, yeah？
W: Uh-hum. It's called dimethylether or DME.
M: Oh, I remember reading something about DME, but I don't remember the chemical terminology. It's mostly used in spray cans, right？
W: Right. DME doesn't destroy the ozone, so it's been environmentally friendly.
M: But doesn't DME pollute the air if it's burned in an engine？
W: Dr. Kelvin said something about its exhausts being clear, that it doesn't release as much pollutants as diesel fuel. And he mentioned something about DME being more efficient than other alternative fuels.
M: When can it replace diesel fuel？
W: Not for a while. It's not economical to mass-produce.
M: Well, thanks for the information. I guess I won't need to borrow your notes.
W: Well, maybe you should look at them. We are having a test next week.
M: Okay, could you give them to Bill Stanford？ I think he is in your psychology class. He is my roommate.
W: Sure. I hope you're feeling better soon.
M: Thanks. Me, too. Bye!
W: Bye!
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"Heavy-robot manufacturers are in some difficulty【53】finding customers. They are offering big【54】just to get in the door. There has been a【55】growth everywhere in the numbers of robots, so we have to admit we are either deceiving【56】or that the market is slowly growing, "said John Reekie, Chairman of Colne Robotics. "The following things must happen【57】the robotics revolution to occur. We must achieve widespread robot literacy (文化),【58】there has been a computer literacy program, there must be a robot literacy campaign. We must also【59】not just a cut in, but a collapse of robot prices【60】,some kind of artificial intelligence needs to be available".
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