首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
专升本
At the first sight the planet Mars does not appear very welcome to any kind of life. It has very little oxygen and water, the te
At the first sight the planet Mars does not appear very welcome to any kind of life. It has very little oxygen and water, the te
admin
2017-09-04
36
问题
At the first sight the planet Mars does not appear very welcome to any kind of life. It has very little oxygen and water, the temperature at night is below 50°C and winds of 100 miles per hour cause severe dust storms. However, the surface of the planet seems to show that water flowed across it some time in the past, and it is believed that there is enough ice at the poles to cover the planet with water if it melts. Although there is no life on the Mars now, some scientists think that there may have been some form of life long time ago. At that time, the planet had active volcanoes; the atmosphere was thicker and warmer; and there was water. In fact, in some ways the Mars may have been similar to the Earth, where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced. The first step would be to warm the planet using certain gases which trap the Sun’s heat in the planet’s atmosphere. With warmth, water and carbon dioxide(二氧化碳) , simple plants could begin to grow. These plants could slowly make the Mars more suitable for living. It is estimated that the whole process might take between 100,000 and 200,000 years. In the meantime, people could begin to live on the planet in special closed environments. They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.
Some scientists think there may have been life on the Mars in the past because________.
选项
A、there is no life there now
B、there is a large amount of water at the poles
C、the Mars may be able to support life in the future
D、conditions may have been similar to those on the Earth
答案
D
解析
第一段最后一句“In fact,in some ways the Mars may have been similar to the Earth,where life exists.”就是“也许火星上过去有生命形式的存在”的原因。故选D。
转载请注明原文地址:https://kaotiyun.com/show/A0iC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
ThereoncelivedapoortailorwhohadasoncalledAladdin,acareless,idleboy【21】woulddonothingbutplayalldaylongint
Inmostcultures,whenyoumeetacquaintancesforthefirsttimeduringaday,itisnormaltogreetthem.Themainpurposeoft
Nowadaysmostpeopledecidequite【61】whatkindofworktheywoulddo.WhenIwasatschool,wehadtochoose【62】whenwewerefif
Muchofaparent’sjobistoprovidethegiftsofcaring,love,andemotionalsupporttochildren.Butonegiftisoftenbeyond
Aroundtheworldmoreandmorepeoplearetakingpartindangeroussportsandactivities.Ofcourse,therehavealwaysbeenpeop
I’vebeengoinghomeforluncheversinceIstartedschool.Ineverlikedeatinginthecafeteria(自助食堂)althoughintileseventh
MostLondoncollegeshavealibrary,withafull-timeorpart-timelibrarian,whowillbeabletogivestudentsinformationont
OurcousinwhoisattendingcollegeinNewYorkphonesuseverySundayatsix,______asclockwork.
Cigarettesmokingisbelievedbymostresearchworkersinthisfieldtobeanimportantfactorinthedevelopmentofcanceroft
Cigarettesmokingisbelievedbymostresearchworkersinthisfieldtobeanimportantfactorinthedevelopmentofcanceroft
随机试题
奥利司他的胃肠道急性不良反应有
急性左心功能不全时,吸氧宜选用
左下颌45678缺失,上下颌间距正常。可摘局部义齿基托后缘应位于
A.胸骨左缘第2肋间可闻及Ⅳ级连续性机器样杂音B.胸骨左缘3~4肋间可闻及Ⅳ级左右收缩期杂音C.胸骨左缘2~4肋间可闻及Ⅲ级左右收缩期喷射音D.胸骨左缘2~3肋间可闻及Ⅲ级收缩期喷射音.肺动脉瓣区第二音亢进固定性分裂E.心尖部可闻及Ⅱ级收缩期杂音
甲、乙、丙、丁拟共同投资设立一有限合伙企业,甲、乙为普通合伙人,丙、丁为有限合伙人。各合伙人经协商后草拟了一份合伙协议。该合伙协议的下列约定中。符合《合伙企业法》规定的是()。
判断肥胖的常用指标包括()。
寂寞的稻草人李汉荣播种时节和谷豆熟了的日子
公安机关人民警察不论职位高低,政治上一律平等,相互之间()。
四项基本原则的内容包括()
Thereasonwhypeopleputonweightatworkisthat
最新回复
(
0
)