首页
登录
职称英语
How is a newborn star formed? For the answer to this question, we mu
How is a newborn star formed? For the answer to this question, we mu
游客
2024-01-11
92
管理
问题
How is a newborn star formed? For the answer
to this question, we must look to the familiar
physical concept of gravitational instability. It is a
Line simple concept, long-known to scientists, having
(5) been first recognized by Isaac Newton in the late
1600s.
Let us envision a cloud of interstellar atoms
and molecules, slightly admixed with dust. This
cloud of interstellar gas is static and uniform.
(10) Suddenly, something occurs to disturb the gas,
causing one small area within it to condense. As
this small area increases in density, becoming
slightly denser than the gas around it, its gravita-
tional field likewise increases somewhat in
(15) strength. More matter now is attracted to the area,
and its gravity becomes even stronger; as a result,
it starts to contract, in the process increasing in den-
sity even more. This in turn further increases its
gravity, so that it accumulates still more matter
(20) and contracts further still. And so the process
continues, until finally the small area of gas gives
birth to a gravitationally bound object, a newborn
star. [br] The author provides information that answers which of the following questions? Ⅰ. How does the small area’s increasing density affect its gravitational field? Ⅱ. What causes the disturbance that changes the cloud from its original static state? Ⅲ. What is the end result of the gradually increas-ing concentration of the small area of gas?
选项
A、Ⅰ only
B、Ⅱ only
C、Ⅰ and Ⅱ only
D、Ⅰ and Ⅲ only
E、Ⅰ, Ⅱ and Ⅲ
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3352345.html
相关试题推荐
Whilebeingquestionedonthecourt,themandenied______theoldlady’snecklac
Itisnoteasy()theanswertothedifficultmathproblem.A、tofigureoutB、figu
Lastyear,heperformedinsevenproductions.去年,他参演了7部作品。
Hewas______enoughtounderstandmyquestionsfromthegesturesImade.A、intelli
Tomakeupanobjectivetest,theteacherwritesaseriesofquestions,______ha
______studentwithalittlecommonsenseshouldbeabletoanswerthequestion.A
Hewas_________enoughtounderstandmyquestionsfromthegesturesImade.A、inte
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
随机试题
【B1】[br]【B4】A、theseB、severalC、theirA本句意为“我们要卖掉这些画…”。
Tomwastryingtosortthroughhis_______andbringthemtosomesortoforder.
[originaltext]W:Hi,Larry,areyouwaitingtoseeProfessorJamison,too?M:Y
目前我国的金融体系中,金融运行主体是()。A.中央银行 B.商业银行 C.
欲比较单位相同、均数相差悬殊资料的变异程度宜用A.标准差 B.百分位数 C.
下列各项,不是亡阴证证候特点的是A.热汗如油 B.肌热烦渴 C.四肢厥冷
哪一组作品是拟人体童话?()A.《皇帝的新装》《王牌肥皂》《神笔马良》 B.《
上市公司发行新股时的招股说明书中,发行人应披露最近3年内募集资金运用的基本情况。
下列关于《巴塞尔新资本协议》下的客户信用评级体系功能的说法中,正确的有()。A
(2019年真题)下列各项中,企业外购材料开出银行承兑汇票支付的手续费,应借记的
最新回复
(
0
)