(含答案)中学英语阅读短文之《火星探测》

阅读短文并回答问题

NASA’s Curiosity vehicle recently recorded the largest level of methane （甲烷）ever measured during its seven-year Mars mission.The discovery is exciting because the existence of methane gas could support the case for life on Mars.

Methane has no color or smell.A special instrument on Curiosity’s Mars Science Laboratory recorded the increased gas level.The device,called a laser spectrometer,measures levels of chemical elements and gases in the Martian atmosphere.In addition to methane,the instrument can record levels of water and CO2.Nearly all the methane gas found in Earth’s atmosphere is produced by biological activity.It usually comes from animal and plant life.But it can also be formed by geological（地质的）processes,such as interactions between rocks and water.NASA said the increased methane was measured to be about21parts per billion by volume(ppbv).One ppbv means that if you take a volume of air on Mars, one billionth of the volume of air is methane.

It was not the first time Curiosity has found methane gas in the Martian atmosphere.About a year ago,NASA announced that Curiosity had discovered sharp seasonal increases in the gas.This time,NASA said the measured methane gas level was clearly larger than any others observedin the past.NASA officials even temporarily stopped Curiosity’s other activities to investigate further.

“It’s exciting because microbial（微生物的）life is an important source of methane on Earth,”NASA said in a statement announcing the discovery. However,Curiosity’s team carried out a follow-up methane experiment that showed a sharp drop in levels of the gas.The second examination found the level was less than one part per billion by volume.That number was close to the background levels Curiosity sees all the time. The rise and fall of the methane gas levels left NASA scientists with more questions than answers.The scientists are continuing to study possible causes for the sudden increase.The methane mystery continues.

Curiosity does not have instruments that can exactly identify whether the source of the methane is biological or geological.One leading theory is that methane is being released from underground areas created by possible life forms that disappeared long ago.Even though Mars has no active volcanoes,scientists believe it is also possible that methane is being produced by reactions involving carbon materials and water.

A clearer understanding of methane levels over time could help scientists determine where they’re located on Mars.Scientists hope this understanding will come as Curiosity continues to collect methane data in its search for possible life.1.Curiosity discovered.

A.the largest methane gas level ever on Mars

B.the existence of life on Mars

C.the reason for the increased methane

D.interactions between rocks and water

2.Why did NASA officials once stop Curiosity’s other activities?

A.To seek possible life existing on Mars.

B.To check the quality of Curiosity’s mission.

C.To find seasonal increases in the methane gas.

D.To further examine the methane gas level on Mars.

3.What can we learn from the last three paragraphs?

A.Causes for the change of methane have been proved by Curiosity.

B.Curiosity has proved the location of methane by instruments.

C.Scientists think underground materials’reactions may produce methane.D.Identifying the source of methane helps scientists search for possible life on Mars.

4.The passage is probably taken from.

A.a geography textbook

B.a science newspaper

C.a health magazine

D.a travel brochure

参

1–4ADCB

生词及长难句

1.NASA美国国家航空航天局

2.Mars n.火星

3.Curiosity’s Mars Science Laboratory“好奇号”火星科学实验室

4.The device,called a laser spectrometer,measures levels of chemical elements and gases in the Martian atmosphere.

句子主干：The device measures levels.参考译文：该装置叫做激光光谱仪，可以测量火星大气中化学元素和气体的含量。

5.laser spectrometer激光光谱仪

6.Martian adj.火星的

7.CO2:carbon dioxide二氧化碳

8.biological adj.生物的；与生命过程有关的；生物学的

Depression is both biological and psychological.抑郁症与生理和心理都有关系。

9.geological adj.地质的

Volcano eruption is one of serious geological disasters.火山喷发是严重的地质灾害之一。

10.interaction n.交互作用，相互作用

Price is determined through the interaction of demand and supply.

价格是通过供需关系决定的。

知识背景

1.NASA美国国家航空航天局（National Aeronautics and Space Administration，简称NASA），又称美国宇航局、美国太空总署，是美国联邦的一个行政性科研机构，负责制定、实施美国的太空计划，并开展航空科学暨太空科学的研究。

2.Mars

火星，太阳系行星之一，是距离太阳由近到远的第四颗行星，属于类地行星。直径约为地球的53%，质量为地球的14%，与地球最近距离约为5500万公里，最远距离则超过4亿公里。其自转轴倾角、自转周期均与地球相近，公转一周约为地球公转时间的两倍。

3.Mars Science Laboratory

火星科学实验室（Mars Science Laboratory,简称MSL），又名“好奇号”火星车。于2011年11月25日在卡纳维拉尔角空军基地发射。它是美国国家航空航天局2009年火星探测计划的一个组成部分，其大小是火星探测漫游者勇气号和机遇号的两倍，重量是其三倍。火星科学实验室将会采集火星土壤样本和岩芯，然后对它们可能支持现在或过去微生物存在的有机化合物和环境条件进行分析。