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【简答题】
阅读理解。 A Battery's Nightmare Portable electronics that can be carried about easily are only as good as their batteries (电池) and, let's face it, batteries aren't very good, especially when compared with, say, petrol, which packs 100 times a battery's energy into an equal space. That's why a large group of mechanical engineers (centered at the Massachusetts Institute of Technology, but with partners at other universities and companies) are hard at work in an effort to replace batteries with a tiny engine that runs on fuel. Imagine a battery-free life! When the fuel runs out in your mobile phone, you just fill up and go. The engine-about the size of a ten-cent coin-starts with a combustion chamber (燃烧室) that burns hydrogen. Its tiny parts are etched (蚀刻) onto silicon wafers (硅片) in the same manner that computer parts are etched onto integrated circuits (集成电路). The first engine is made up of five wafers. And since these wafers could be produced in much the same way as computer chips, they could probably be produced quite cheaply. But the devil in all this nice detail is efficiency. Tiny engine parts don't always behave like the bigger parts of the first engine. Something between the parts can slow down the works, according to Columbia University Professor LucFrechette, one of the engine's designers. Extreme heat from the combustion chamber is also a problem, often leaking to other parts of the engine. The scientists' goal is to create an engine that will operate 10 times better than batteries operate. Frechette says that a complete system, with all parts in place and working, will be set up in the next couple of years, but commercial models aren't likely until at least the end of the next ten years. 1. According to the passage, the title suggests that ______. [     ] A. batteries should be greatly improved B. petrol will be used instead of batteries C. the time of batteries will be gone forever D. pollution problems caused by batteries must be solved 2. What's the meaning of the underlined word 'devil' in paragraph 3? [     ] A. Problem B. Advantage C. Invention D. Technique 3. What can we infer from the passage? [     ] A. The new invention doesn't need any fuel. B. The new engine has been produced in large quantities. C. The new invention is much cheaper than the battery. D. The new engine needs to be improved before it's on sale.
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【单选题】有赖T细胞辅助才能刺激B细胞产生抗体的抗原是( )
A.
T细胞依赖性抗原
B.
T细胞非依赖性抗原
C.
异嗜性抗原
D.
异种抗原
【多选题】元素的组合方式,包含哪三种?
A.
第一种是邻接式组合,各个独立的形态元素并置或通过第三元素连接。
B.
第一种是穿插式组合,形态元素之间相互重叠但不包容,形态可以相加或相减
C.
第一种是邻接式组合,各个独立的形态元素并置或通过第二元素连接。
D.
第一种是包容式组合,被包容的元素成为了另一元素的内部,分封闭和半封闭两种方式
【单选题】材料力学的任务是( )
A.
研究材料的组成
B.
研究各种材料的力学性能
C.
在既安全又经济的原则下,为设计构件提供分析计算的基本理论和方法
D.
在保证安全的原则下设计构件的结构
【多选题】在安全人机工程学研究中,下列哪些人的基本特性属于重要研究范畴?
A.
外貌
B.
身高
C.
心理
D.
神态
【单选题】下列结论中,只有( )是正确的
A.
材料力学的任务是研究材料的组成
B.
材料力学的任务是研究各种材料的力学性能
C.
材料力学的任务是在既安全又经济的原则下,为设计构件的结构提供分析计算的基本理论和方法
D.
材料力学的任务是在保证安全的原则下设计构件的结构
【单选题】下列结论中,( ) 是正确的。
A.
材料力学的任务是研究各类材料的力学问题
B.
材料力学的任务是在保证安全的原则下设计构件或零件
C.
材料力学的任务是在力求经济的原则下设计构件或零件
D.
材料力学的任务是在保证安全、经济的原则下为设计构件提供分析、计算的基础理论和方法
【判断题】判断矿体位置可利用元素分带、元素对比值、晕中的指示元素组合和含量特征。()
A.
正确
B.
错误
【单选题】食管脱落细胞学检查时,下述哪项支持食管癌的诊断( )(1998年)
A.
出现大量鳞状上皮细胞
B.
出现中性粒细胞
C.
出现大量腺上皮细胞
D.
出现核大、深染、核仁明显的细胞
E.
出现大量红细胞
【单选题】兴奋性是指()
A.
细胞兴奋的外在表现
B.
细胞对刺激产生动作电位的能力
C.
细胞对刺激产生反应的过程
D.
细胞对刺激产生动作电位的全过程
E.
机体对刺激发生反射的过程
【判断题】Th1细胞产生的IL-2能刺激CTL、NK细胞进行增殖,但不能刺激Th1细胞本身进行增殖。
A.
正确
B.
错误
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