SECTION B PASSAGES
Directions: In this section, you will hear several passages. Listen to the passages carefully and then answer the questions that follow.
听力原文: Are electric cars the way of the future? Automobile manufactures are under pressure to develop ca rs that do not pollute. One powerful motive is a California law requiring that by the year 2000 ten percent of new car sells in the state be so called zero-emission vehicles. These cars must put no pollutants whatsoever into the atmosphere.
California is a huge market for the automobile companies, so they are working hard to meet these standards. So far the electric car seems to be the best alternative. So the big advantage of electric cars is that they don't pollute. However they will be in competition with gas-powered cars and that's where the weaknesses come out.
The big problem is that the batteries that power electric cars weigh a lot relative to the amount of power they deliver. For instance, in one prototype electric car, the batteries weighed 400 kilograms. And they provide enough energy to go 250 kilometers before recharging, which takes eight hours. Compare that to a moderately fuel-efficient conventional car, it can go 600 to 700 kilometers on a tank of gas and refilling takes just minutes. If there are other drains on an electric car's batteries besides the motor, headlights, air conditioning or a heater, its already limited range will be significantly reduced. So automobile engineers are trying to make more powerful batteries that would increase the cars' range and make them more attractive to buyers.
What is the talk' mainly about?
A.Automobile safety.
B.Increasing fuel efficiency.
C.California's pollution laws.
D.Electric-powered cars.
第1题
关于外阴白色病变哪项叙述是错误的()
A、外阴白色病变亦称慢性外阴营养不良
B、增生型病变区皮肤发白增厚似皮革
C、苔藓型病变区皮肤萎缩变薄变白
D、混合型病变区有增生与苔藓型两种病变
E、萎缩型较易出现非典型增生
第2题
外阴色素减退性疾病又称:
A.外阴癌前病变
B.外阴不典型增生
C.外阴白色病变
D.外阴癌
E.非特异性外阴炎
第3题
外阴色素减退性疾病又称
A.外阴癌前病变
B.外阴不典型增生
C.外阴白色病变
D.外阴癌
E.非特异性外阴炎
第8题
A.外阴白色病变的病因是念珠菌
B.外阴硬化性苔癣的病因可能与遗传、自身免性疾病、男性激素不足有关。
C.外阴鳞状上皮增生常继发癌变
D.外阴白色病变病理变化恒定,任何病变区域一次活检均能诊断
E.治疗原则以手术切除为宜
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