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
外语
Eta Carinae As possibly the galaxy’s (银河) most massive star, Eta Carinae is now engaging in some very unusual behaviour. Austra
Eta Carinae As possibly the galaxy’s (银河) most massive star, Eta Carinae is now engaging in some very unusual behaviour. Austra
admin
2009-06-15
38
问题
Eta Carinae
As possibly the galaxy’s (银河) most massive star, Eta Carinae is now engaging in some very unusual behaviour. Australian astronomers, being in the Southern Hemisphere (半球), are able to observe it clearly.
In the 19th century, Eta Carinae was for a time the third brightest star in the sky. It has now become less bright so that binoculars ( 双筒望远镜) are needed to see it. "It seems to be brightening and becoming less bright over a period of many years", said Dr Bob Duncan from the Australia Telescope National Facility.
While it is not unusual for stars to vary in brightness, the period is usually much shorter. "Since 1992 it has become four times brighter, and then last year it began to drop dramatically," he said.
The problem in observing Eta Carinae is that it has been surrounded by a cloud of gas and dust, making it hard to see the star directly. However, radio waves and infrared light, (红外线) can pass through this cloud, so telescopes that receive these wavelengths can observe what is occurring.
Eta Carinae is of particular interest to astronomers because it seems to be in its death throes (剧痛). Being so large it will end up as a supernova (超新星). There has not been a supernova in our galaxy since the invention of the telescope. While a 1987 explosion in a nearby galaxy gave astronomers plenty of valuable data, they are hungry for an even closer look.
Eta Carinae has other unique features, and is the only star known to produce an ultraviolet (紫外线) laser that is brighter than that produced by the Sun. Lasers have been observed in other frequencies from a few stars.
选项
A、some very common behaviour.
B、some very dull behaviour.
C、some very frightening behaviour,
D、some very strange behaviour.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/U4hd777K
本试题收录于:
职称英语理工类C级题库职称英语分类
0
职称英语理工类C级
职称英语
相关试题推荐
SincetheGreatDepression,theUnitedStatesgovernmenthasprotectedfarmersfromdamagingdropsingrainprices.
SomeUnusualCelebrationsSomeholidaysarewell-knownallaroundtheworld.AmongthemareNewYearsEvecelebrations.Al
Thecompanyhastherighttoendhisemploymentatanytime.
AnimportantpartofthenationalgovernmentistheForeignService,abranchoftheDepartmentofState.
A.recoverfromdiseasequicklyB.thereisnotenoughhardevidenceC.usetheirmindsactivelyD.itimprovesgeneralwell-bei
Hewastemptedbythehighsalaryofferedbythecompany.
IntheUS,aperson’scompanybuyshimorherhealthinsurance.IntheUS,graduatedstudentswithnojobscanbuyuniversityh
LifetimeemploymentintheJapanesecompanymeansthattheemployeeLifetimeemploymentinfluencesone’s
随机试题
关于最优证券组合,以下说法正确的是()。
偶然性因素
ADSL的中文全称是()
唯美公司是湖南省衡阳市一家生产并销售护肤品的公司,为了吸引更多的顾客,于是让空盛公司宣传其公司的产品,空盛公司按照唯美公司的材料为其设计制作了虚假宣传广告短片,下列选项中不正确的是哪些?
楼梯梯级的墙壁或墙面边界层宽度(疏散路径有效宽度)为()mm。
政策性金融机构的经营原则为()。
根据卡特尔的智力理论,晶体智力在30岁后,是随着年龄的增长而()。
“泪眼问花花不语,乱红飞过秋千去。”按照王国维在《人间词话》中的说法,在“有我之境”“无我之境”二者中属于()。
在报表设计的众多控件属性中,能够唯一标识控件的是【】属性。
[A]claiming[B]crimes[C]faster[D]giving[E]growing[F]host[G]lawless[H]people[I]police[J]rarely[K]slow
最新回复
(
0
)