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听力原文:W: Today' s guest on 'Science Update' is David Brown. Dr. Brown, you and your team have found bacteria far below the Earth' s surface. You must be thrilled about your discovery. M: Well, yes, it' s very exciting. For a long time, we' d suspected the presence of such organisms, but we lacked substantial evidence. W: How did you confirm the existence of the bacteria? M: Well, technology helped. Our drilling techniques have improved significantly, and so the risk that surface bacteria could be mistaken for those found at much greater depth was reduced. With the new techniques, we could get much deeper into the Earth. W: How far down did you actually get? M: In one case, about three kilometers. We were surprised, I must tell you, that there were organisms that far down. W: You know, it sounds like fiction, something like a lost world. M: Let' s call it a hidden biosphere, and it' s probably a very extensive one. The mass of the living organisms below the surface may be equal in size to the mass of the surface bacteria. W: Have you found any unique life-forms? M: Yes. One of the organisms is the first anaerobic bacillus ever discovered. That means it can live and grow only where there is no oxygen. W: Is there any danger of these bacteria infecting people when you bring them to the surface? M: The bacteria in question were adapted to an environment that' s hostile and alien to humans. Conversely, these anaerobic bacteria could not survive in our environment. So we really don' t need to worry about these bacteria causing illnesses in people. (20)
A.
The presence of life-forms far below the Earth's surface.
B.
The risk of infection from rare strains of bacteria.
C.
Fictional representations of a hidden underground world.
D.
The reliability of evidence collected by new drilling methods.
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【多选题】关于洗面奶以下说法中正确的是:()
A.
溶剂型洗面奶主要针对油性污垢
B.
根据使用目的不同可分为普通型、磨砂型、疗效型
C.
合成型清洁剂性质温和,刺激性较肥皂明显减小
D.
皂类清洁剂是由脂肪、油脂及盐组成的pH为9.5~10的碱盐
【单选题】女性,28岁。高热寒战,肺部听诊可闻及胸语音,该患者的诊断可能是
A.
胸腔积液
B.
肺脓肿空洞
C.
大叶性肺炎
D.
空洞型肺结核
E.
支气管扩张
【单选题】正弦量的三要素包含振幅、角频率和()。
A.
初相
B.
相位
C.
相位差
D.
频率
【多选题】关于洗面奶以下说法正确的是:
A.
泡沫型洗面奶对油性污垢清洁能力较强
B.
根据使用目的的不同可分为普通型、磨砂型、疗效型
C.
合成型清洁剂性质温和,刺激性较肥皂明显减小
D.
皂类清洁剂是由脂肪。油脂及盐组成的pH为9.5~10的碱盐
E.
溶剂型洗面奶主要针对油性污垢
【单选题】某伺服电动机最高大输出转矩为5N·m,通过齿轮系5:1减速,可带动()的最大转矩负载。
A.
25N·m
B.
50N·m
C.
2.5N·m
D.
1.25N·m
【多选题】关于洗面奶以下说法正确的是:
A.
根据使用目的的不同可分为普通型、磨砂型、疗效型
B.
合成型清洁剂性质温和,刺激性较肥皂明显减小
C.
皂类清洁剂是由脂肪。油脂及盐组成的pH为9.5~10的碱盐
D.
溶剂型洗面奶主要针对油性污垢
E.
泡沫型洗面奶对油性污垢清洁能力较强
【单选题】直流伺服电机具有优良的调速性能,但却存在一些固有的缺点。以下关于直流伺服电机的描述,哪个是错误的呢?
A.
它的电刷和换向器易磨损,需要经常维护;
B.
由于换向器换向时会产生火花,使电动机的最高转速受到限制,也使应用环境受到限制;
C.
直流电动机的结构复杂,制造困难,所用铜铁材料消耗大,制造成本高。
D.
直流伺服电机的励磁线圈,装在转子上,电压调整很不方便。
【单选题】伺服电机βis4/4000的最高转速为
A.
3000r/min
B.
2000r/min
C.
4000r/min
D.
5000r/min
【单选题】女性患者,26岁,高热寒战,肺部听诊可闻及胸语音,谊患者的诊断可能是
A.
胸腔积液
B.
肺脓肿空洞
C.
空洞型肺结核
D.
大叶性肺炎
E.
支气管扩张
【多选题】关于洗面奶以下说法正确的是:
A.
溶剂型洗面奶主要针对油性污垢
B.
根据使用目的的不同可分为普通型、磨砂型、疗效型
C.
无泡型洗面奶对油性污垢清洁能力较强
D.
合成型清洁剂性质温和,刺激性较肥皂明显较小
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