首页
登录
职称英语
Lunar sight-seeing trips and orbiting space hotels are within reach, moon wal
Lunar sight-seeing trips and orbiting space hotels are within reach, moon wal
游客
2023-12-21
39
管理
问题
Lunar sight-seeing trips and orbiting space hotels are within reach, moon walking astronaut Edwin"Buzz" Aldrin said last week, but some who favor space tourism worried about its "giggle factor". Astronomers have known for years that a source of intense energy emissions lies at the center of the Milky Way Galaxy, obscured from view by vast clouds of dust and gas. In February, 1992, researchers at the Max Planck Institute in Garching, Germany, reported evidence that the mysterious energy source is a gigantic black hole.
Observations have shown that many strong energy sources lie at the heart of the Milky Way. One of them, called Sagittarius A, is thought to be the actual center of the Galaxy, the point about which the great spiral of stars rotates. Sagittarius A is a powerful emitter of radio waves and X-rays.
Astronomers have considered two possible explanations for the identity of Sagittarius A. They theorized that it is either a compact duster of normal stars or a super-massive black hole containing as much as a million or more suns. The German scientists reported that they found strong evidence in support of the black hole explanation.
The astronomers used a new telescope high in the Andes Mountains of Chile to obtain the sharpest images ever made of the region around Sagittarius A. The image shows that Sagittarius A is a single, small object rather than a duster of stars.
The researchers also found that a bubble of gas is expanding outward from Sagittarius A. This expanding gas is similar in temperate, density, and composition to the jets of gas that astronomers have observed flow hag away from the centers of many other galaxies. Such jets are thought to be generated by accretion disks surrounding enormous black holes. Accretion disks are vast, swirling masses of gas and dust that give off titanic amounts of energy as they are sucked into the black hole. The similarity between the jets emitted by some galaxies and the gas bubble surrounding Sagittarius A supports the idea that Sagittarius A is a super-massive black hole. [br] It may be inferred from the passage that jets of gas ______.
选项
A、around Sagittarius A were found quite unexpectedly
B、are common phenomena surrounding enormous black holes
C、only flow away from the centers of galaxies
D、are the true source of intense energy
答案
B
解析
根据文章第五段第二和第三句话“This expanding gas is similar in temperature,density,and com position to the jets of gas that astronomers have observed flowing away from the centers of many other galaxies.Such jets are thought to be generated by accretion disks surrounding enormous black holes,”可以推断出[B]为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3291637.html
相关试题推荐
Mostearthquakesoccurwithintheupper15milesoftheearth’ssurface.But
Mostearthquakesoccurwithintheupper15milesoftheearth’ssurface.But
Lunarsight-seeingtripsandorbitingspacehotelsarewithinreach,moonwal
Lunarsight-seeingtripsandorbitingspacehotelsarewithinreach,moonwal
Lunarsight-seeingtripsandorbitingspacehotelsarewithinreach,moonwal
Lunarsight-seeingtripsandorbitingspacehotelsarewithinreach,moonwal
Lunarsight-seeingtripsandorbitingspacehotelsamwithinroach,moonwalk
Lunarsight-seeingtripsandorbitingspacehotelsamwithinroach,moonwalk
TheFamilyThenandNow Thingswerenevereasywithinthefam
TheFamilyThenandNow Thingswerenevereasywithinthefam
随机试题
FortheAMAT.in1998,theSalesareexpectedtoreach______.[br]TheSaleso
[originaltext]Everyonewillbecomeoldandretiresomeday.Soit’sneverto
Iamoftenaskedtodescribetheexperienceof______(抚养一个残疾孩子).raisingadisable
NewresearchfromtheUnitedStatessuggeststhatthemillennia-oldtherapy
Exceptionalchildrenaredifferentinsomesignificantwaysfromothersoft
Thereisnothingworsethansomeonewhoisalwayslate.Latenesscanbea
根据《出版专业技术人员职业资格管理规定》和《出版专业技术人员继续教育暂行规定》,
(2020年真题)下列属于征税对象数额或相对比例越大,规定的等级税率越高情形的税
根据《建设工程施工合同(示范文本)》(GF-99-0201),关于工程变更程序的
混凝土浇筑仓内采用喷雾措施进行降温,一般在混凝土( )后结束喷雾。A.浇筑完成
最新回复
(
0
)