首页
登录
职称英语
Astronomers have had difficulty accounting for certain planets discovered ou
Astronomers have had difficulty accounting for certain planets discovered ou
游客
2024-01-10
38
管理
问题
Astronomers have had difficulty accounting for certain planets discovered outside our solar system. They are called hot Jupiters because each is similar in mass to Jupiter, the largest solar-system planet, but orbits its parent star at a fraction of the distance at which
Earth
, let alone Jupiter, orbits the Sun. In the standard, solar-system-based theory of planetary formation, such as a massive planet could not form so close to a star. So most attempts to explain a hot Jupiter’s existence envision it forming farther away, then migrating inward. According to one hypothesis, the planet’s gravitational field tugs on the protoplanetary disk of dust and gas from which it formed. The disk exerts its own gravitational tug, and this interplay of forces robs the planet of momentum in its orbital path, forcing it to spiral in toward the star. According to another hypothesis, the planet’s gravitational field is so strong that it creates a groove in the disk, partitioning it into inner and outer regions; the resulting gravitational interactions between the planet and these regions cause the planet to lose orbital momentum and spiral inward. Another question remains: what prevents the planet from continuing its spiral until it collides with the star? [br] The author of the passage mentions “Earth” primarily in order to
选项
A、stress the massive size of a hot Jupiter
B、emphasize the proximity of a hot Jupiter to its parent star
C、imply that hot Jupiters are unlikely to harbor extraterrestrial life
D、point out differences between Earth and Jupiter with regard to their orbital distance from the Sun
E、illustrate how hot Jupiters might fit into the standard theory of planetary formation
答案
B
解析
“地球”所在句子的3s版本是为了提出一个问题:为什么热木星距离恒星那么近,因此选项B正确。D项要注意“木星”和“热木星”是不一样的概念。
转载请注明原文地址:http://tihaiku.com/zcyy/3349501.html
相关试题推荐
Therootsystemsofcertainplantfamilies,suchasthatoftulipsandcrabgrass
PRESUMPTUOUS:A、helpfulB、despicableC、certainD、daintyE、modestE
Theywerecertainthatthisproblem,likesomanyother______problems,didnote
Despitecertain______habitsoftheNorthAmericanscreechowl,itperformsthem
Perfectcertaintybelongsonlytothegods;therestofushavetomakedowith
Britishpoliticalscientistsoncehaddifficultyunderstandinghowtheunbalanci
CORROBORATION:A、impossibilityB、uncertaintyC、insufficiencyD、disuseE、specifica
Sendingarobotintospacetogatherinformationiscertainlyaviab
Sendingarobotintospacetogatherinformationiscertainlyaviab
ASSIMILATE:A、toascertainB、tobefuddleC、tosuffocateD、todissipateE、toincor
随机试题
[originaltext]Agoodmarriagemeansgrowingasacouplebutalsogrowingas
ManystudentsarerelyingonInternetandothertechnologiesfortheirlangu
WhaleFalls1.Thewhaleisakindofmarinemammal■【T1】_________size
SlashYourBills—6WaystoKeepMoreCash
患儿男,5岁。因发热2天,出现左上下肢无力1天入院。2天前无明显诱因发热,体温4
腰椎间盘突出症与腰椎管狭窄症临床症状的主要不同之处在于A.腰痛及下肢放射痛的程度
在住宅项目价格制定过程中,核心均价的确定有很多种方法,包括( )。A.市场提取
我国房地产经纪行业中较早发展起来,且市场参与度尚不够高的房地产经纪机构是( )
女,26岁,足月分娩后12个月后出现持续的阴道不规则流血,血β-hCG持续高水平
在编制财务报表前,需要完成下列工作中,正确的是()。A、严格审核会计账簿记录和有
最新回复
(
0
)