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U.S. Scientists Confirm Water on Mars NASA scientists said that Mars was covered once by vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life. Laboratory tests aboard NASA's Phoenix Mars Lander have identified water in a soil sample. The lander's robotic arm delivered the sample Wednesday to an instrument that identifies vapors produced by the heating of samples. 'We have water,' said William Boynton of the University of Arizona, lead scientist for the Thermal and Evolved-Gas Analyzer, or TEGA. 'This is the first time Martian water has been touched and tasted. ' The robotic arm is a critical part of the Phoenix Mars mission. It is needed to trench into the icy layers of northern polar Mars and deliver samples to instruments that will analyze what Mars is made of, what its water is like, and whether it is or has ever been a possible habitat for life. The soil sample came from a trench approximately 2 inches deep. When the robotic arm first reached that depth, it hit a hard layer of frozen soil. Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop. Most of the material in Wednesday's sample had been exposed to the air for two days, letting some of the water in the sample vaporize away and making the soil easier to handle. 'Mars is giving us some surprises,' said Phoenix principal investigator Peter Smith of the University of Arizona. 'We're excited because surprises are where discoveries come from. One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck, different from what we expected, from all the Mars simulation testing we've done so far. ' Since landing on May 25, Phoenix has been studying soil with. a chemistry lab, TEGA, a microscope, a conductivity probe and cameras. The science team is trying to determine whether the water ice ever thaws enough to be available for biology and if carbon-containing chemicals and other raw materials for life are present. The mission is examining the sky as well as the ground. A Canadian instrument is using a laser beam to study dust and clouds overhead. 'It's a 30-watt light bulb giving us a laser show on Mars,' said Victoria Hipkin of the Canadian Space Agency. A full-circle, color panorama of Phoenix's surroundings also has been completed by the spacecraft. 'The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see,' said Mark Lemmon of Texas A & M University, lead scientist for Phoenix's Surface Stereo Imager camera. 'They help us plan measurements we're making within reach of the robotic arm and interpret those measurements on a wider scale. ' What was discovered by NASA's Phoenix Mars Lander on Mars?
A.
Vast lakes.
B.
Flowing rivers.
C.
Water in a soil sample.
D.
Living things.
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【简答题】口语作业:完成1则求职面试相关的对话,要求不少于10句话。
【单选题】有关急性播散性脑脊髓炎的辅助检查不正确的是()
A.
外周血白细胞增多,血沉加快
B.
脑脊液压力增高或正常,CSF-MNC增多
C.
CSF蛋白明显增高,以IgM增高为主
D.
EEG常见弥漫的θ和δ波,亦可见棘波和棘慢复合波
E.
MRI可见脑和脊髓白质内散在多发的T 1 低信号、T 2 高信号病灶
【简答题】原电池电动势的测试 (20分) ( 1 )硫酸铜和硫酸锌组成的原电池装置测试中,如果导线与电极或伏特计间接触不良,对电动势会产生什么影响?为什么? ( 2 )在硫酸铜的烧杯中加入浓氨水,电动势变 ( 3 )继续在硫酸锌的烧杯中加入浓氨水,电动势变 ( 4 )比较三次测量结果,说明浓度对电极电势的影响。
【单选题】本次实验中,基本的积分电路实验数据测量时,用()测量。
A.
万用表直流电压档
B.
万用表交流电压档
C.
万用表直流电流档
D.
万用表交流电流档
【多选题】【检索题】利用万方的《中外专利数据库》,查找与“心脏起搏器”相关的专利。以下说法正确的是()。
A.
“心脏起搏器”是否选择精确匹配对检索结果没有影响。
B.
最新公开的专利是“埋藏式心脏起搏器电极线”,于2020年3月公开。
C.
检索到的专利中,法律状态有有权、无权和在审三种。
D.
检索到的专利以实用新型居多。
【单选题】拔牙后向病人交代注意事项时,错误的是
A.
咬住创口上的纱卷,30min后取出
B.
术后1d内唾液中可混有少量血丝
C.
拔牙后2h漱口,保持口腔清洁
D.
宜吃偏冷,偏软的食物
E.
拔牙7d后拆线
【单选题】下列关于急性脊髓炎的脑脊液检查说法不正确的是()
A.
压力正常
B.
细胞数正常或轻度增高
C.
蛋白含量正常或轻度增高
D.
糖和氯化物浓度升高
【多选题】关于拔牙后的注意事项说法正确的是( )。
A.
咬住创口上纱球,40分钟后取出
B.
宜吃温凉、稀软的食物
C.
拔牙后2小时应漱口,保持口腔清洁
D.
拔牙一般可以不吃药
E.
术后一天内唾液中混有血丝是正常的
【单选题】以下匹配方式检索结果最多的是( )
A.
后方一致
B.
前方一致
C.
中间一致
D.
精确一致
【单选题】患者,男,50岁。右下颌第二磨牙残冠,局部无炎症,拟行拔除。拔牙后的注意事项中,不正确的是()
A.
咬住创口上的纱卷30分钟
B.
术后1天内涎液中可混有少量血丝
C.
拔牙后2小时漱口,保持口腔清洁
D.
宜吃偏冷,偏软的食物
E.
拔牙7天后拆线
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