U. S. Scientists Confirm Water on Mars NASA scientists said that Mars was covered once by vast lakes, flowing rivers and a v

admin2012-09-10  46

问题               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. "
Which of the following do you think is the best description of Phoenix’s Surface Stereo Imager camera, according to your understanding of the passage?

选项 A、It imitates human vision and is able to capture three-dimensional images.
B、It imitates human voice and is able to record slight sounds while taking photos.
C、It takes clear photos that show every detail of the object.
D、It is this particular type of camera that can take wide angle pictures.

答案A

解析 选项B“它模仿人的声音并能在拍照的时候录取轻微的声音”在文中并未提到这个功能。选项C“照片拍的特别清晰并能展示物体的每一个细节”,这一点也并未在文中着重说明。选项D“是一种可以广角拍摄的特殊种类的照相机”,没有在文中明确提及。而选项A“它能模仿人类的视角并获取三维图像”,这个正是文中对此照相机的描述。所以选A。
转载请注明原文地址:https://jikaoti.com/ti/3CJsFFFM
0

最新回复(0)