首页
登录
职称英语
Mounting evidence has led astronomers to just an improbable conclusion; At
Mounting evidence has led astronomers to just an improbable conclusion; At
游客
2024-10-30
32
管理
问题
Mounting evidence has led astronomers to just an improbable conclusion; At least 90 percent and possibly 99 percent of all matter in the universe is completely【C1】______ . Astronomers call this stuff dark matter.
An astronomer first reported the matter after noting some unusual behaviour in visible matter. In 1993, Swiss astrophysicist Fritz Zwicky concluded that 【C2】______ was causing strange gravitational effects【C3】______ these galaxies.
Galaxies are like【C4】______ islands in deep space【C5】______ billions of stars that are held together by the force of【C7】______ .Some galaxies are part of【C6】______ systems called clusters; which contain many galaxies. Most galaxies; belong to smaller systems called groups. Groups and clusters in 【C8】______ form even larger【C9】______ known as super-clusters. Just【C10】______ the force of gravity keeps stars together in galaxies the force of gravity【C11】______to keep galaxies together in clusters~
This same force of gravity keeps planets【C12】______ around the sun【C13】______ flying off into space. How great a force gravity exerts depends on the mass of the objects【C14】______ and the distance between them, a【C15】______ discovered by Newton. The amount of mass and the distance between objects also【C16】______ how fast the objects travel as they orbit each other. The force of its gravity keeps Earth and the other planets【C17】______ orbit around it. The orbital speeds of the planets【C18】______ with increasing distance from the sun. The planet nearest to the sun travels at an orbital speed of 48 kilometers per second【C19】______ the distant planet Pluto orbits【C20】______ speed of 7 kilometers per second [br] 【C11】
选项
A、appears
B、used
C、resorts
D、is sure
答案
A
解析
表不确定。
转载请注明原文地址:https://tihaiku.com/zcyy/3823623.html
相关试题推荐
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
Mountingevidencehasledastronomerstojustanimprobableconclusion;At
随机试题
[originaltext]Iamnotonlyapainter,butastudentofart.Sometimes,[20]
[originaltext]M:IhopeyouwillspendNewYear’sEvewithus.W:I’dloveto,
某北方地区框剪结构病房楼,地上19层,地下2层,一般装修,其建安工程单方造价为3
A.11.12 B.10.12 C.9.12 D.8.12
A.乳糜微粒 B.三酰甘油 C.胆固醇 D.高密度脂蛋白(HDL) E.
以下关于不良反应的论述何者不正确:A.副作用是难以避免的 B.变态反应与药物剂
关于钩端螺旋体病的流行病学,下列哪项是错误的A.病后可获得较强的同型免疫力及异型
一退休教师,小腿青筋怒张、迂曲20余年,久站久行或劳累时青筋迂曲加重,伴下坠不适
下列情形,不可以推定经营者具有市场支配地位的是()。A、一个经营者在相关市场的市
派出所民警讯问公共汽车上的一桩盗窃案的嫌疑人甲、乙、丙、丁的笔录如下: 甲说:
最新回复
(
0
)