Mars(火星)appearstobeflowingwithsmallstreamsofsaltywater...
问题详情:
Mars( 火星) appears to be flowing with small streams of salty water, at least in the
summer, scientists reported Monday. "It suggests that. it would be possible for there to
be life today on Mars," NASA's science mission chief, John Grunsfeld, said at a news
conference on September 28, 2015.
The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said.
"What we're dealing with is wet soil. thin layers of wet soil, not standing water," said
Aifred McEwen of the University of Arizona at Tueson ! the principal scientist for the
Mars Reconnaissance Orbiter's high-resolution imaging experiment.
Because liquid water is essential to life, the findings could have major implications
for the possibility of Martian life. The researchers said further exploration is needed to
determine whether microscopic life exists on the planet.
The presence of liquid water could also make life easier for astronauts visiting or
living on Mars. Water could be used for drinking and for creating oxygen and rocket
fuel. NASA's goal is to send humans there in the 2030s.
The evidence of flowing water consists largely of dark, narrow streaks(条痕) on
the surface that tend to appear and grow during the warmest Martian months and fade
the rest of the year.
Mars is extremely cold even in summer, and the streaks are in places where the
temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing
point of water and melt ice.
The source of the water is a mystery. Scientists noted it could be melting
ice. It could be an underground aquifer, which is rock or sand that can hold water. It is
possibly water vapor from the thin Martian atmosphere, Or it may be a combination
Michael Meyer, lead scientist for NASA's Mars exploration program, said the only
definitive way for now to determine whether there's life on Mars is to collect rocks and
soil for analysis on Earth - something a U. S. lander set for lift-off in 2020 will do.
28. What would be the best title for the text? '
A Streams of Water Spotted on Mars B. Astronauts will Land on Mars
C. NASA's Mars Exploration Program D. A Breakthrough in the Exploration of Mars
29. According to John Grunsfeld, there seems to be on Mars.
A. salty water B. standing water C. rocket fuel D. human beings
ntists are uncertain about the of the water on Mars.
A. state B. source C. temperature D. taste 31. What matters to the existence of liquid water on Mars?
A. The distance from the sun. B. The favorable climate.
C. The gravity of the earth D.The salt in it.
【回答】
AABD
知识点:科普环保类阅读
题型:阅读理解
-
某商品进价是1000元,售价为1500元.为促销,商店决定降价出售,但保*利润率不低于,则商店最多降 元...
问题详情:某商品进价是1000元,售价为1500元.为促销,商店决定降价出售,但保*利润率不低于,则商店最多降元出售商品.【回答】450元. 知识点:一元一次不等式题型:解答题...
-
下列化学用语表达正确的是( )A.羟基的电子式 B.乙烯的结构简式是CH2CH2C.醛基的结...
问题详情:下列化学用语表达正确的是()A.羟基的电子式 B.乙烯的结构简式是CH2CH2C.醛基的结构简式是—COH D.淀粉的分子式是(C6H10O5)n【回答】D知识点:糖类油脂蛋白质单元测试题型:选择题...
-
阅读下面的文字,完成14―17题。凄与悲的距离白水河听《二泉映月》,在优美的乐曲中,你能感受到一种感伤,一种凄...
问题详情:阅读下面的文字,完成14―17题。凄与悲的距离白水河听《二泉映月》,在优美的乐曲中,你能感受到一种感伤,一种凄凉。它这样的美,美得让人陶醉,它这样的凄怨,凄怨得让人落泪。深入它,才知道它凝聚了一位贫苦艺术家一生的感慨、叹伤,它又凝聚了他一生的流浪。阿炳,这...
-
下列说法正确的是 A.物质发生化学反应都伴随着能量变化B.伴有能量变化的物质变化都是化学变化C.在一个确...
问题详情: 下列说法正确的是 A.物质发生化学反应都伴随着能量变化B.伴有能量变化的物质变化都是化学变化C.在一个确定的化学反应关系中,反应物的总能量总是高于生成物的总能量D.放热反应的发生无需任何条件【回答】A知识点:化学反应中的能量变化题型:选择题...
相关文章
- NewYorkStatehaspassedtheUSA’sfirststatelawbanning(禁止)mo...
- —Mike,itsreallyimpossibleforustogettotherailwaystation...
- Hesaystheproblemwithteachersis,“Whatwillakidlearnfroms...
- Nomatterwhatproblemwe’refacing,wealwaysfindsolutions.
- Mars(火星)appearstobeflowingwithsmallstreamsofsaltyw...
- Ifoverweightpeopleeatlessandtakemoreexercise,they’llso...
- Stillwonderwheretostay?Wehavealottooffer.GUESTROOMSSpac...
- Inthefuture,peoplemaytraveltoMars(火星)bywater-poweredspa...
- Mars(火星)appearstobeflowingwithsmallstreamsofsalty...
- SurprisingwaystobeatstressWeallhavetimeswhenwefeellikew...