Eta Carinae As possibly the galaxys most massive star, Eta Carinae is now engaging in some very unusual behaviour. Australian astronomers, being in the Southern Hemisphere , are able to observe it clearly. 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. Eta Carinae is of particular interest to astronomers because it seems to be in its death throes. Being so large it will end up as a supernova . 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. 31. Eta Carinae is now engaging in C. some very frightening behaviour. D. some very strange behaviour A. over which star vary in brightness C. Eta carinae takes to become a supernova. 33. Eta Carinae is hard to observe because C. the binoculars are not powerful enough.D. it does not send out infrared light. A. it is in its final stage. B. it is a supernova. 35. Which of the following statements about Eta Carinae is NOT true? B. It can be seen only through binoculars. D. Its ultraviolet laser is brighter than that of the Sun.
如何做到一天记住100个单词
建议懒人背单词的方法
雅思单词分类综合学习法
背单词其实也很轻松--拆字法
一个月搞定6500个雅思单词小case
教你一个月搞定6500个雅思单词
如何高效积累雅思词汇-阅读篇
如何准确构建双边讨论型文章
如何使单词“记而不忘”
谐音法背单词 雅思备考其实也轻松
20天轻松攻克雅思单词
备考策略:如何突破雅思5000词汇
雅思词汇:如何过目不忘-废物时间法
以词记词之“小试牛刀”
学英语背单词的关键:学会应用
关于背单词的一点个人体会(1)
如何高效积累雅思词汇-写作篇
专家指导:科学有效地搞定雅思单词
雅思单词轻松背-音像法
背单词方法--大家参考分享
背单词其实也很轻松--对比法
如何准备雅思词汇
背单词其实也很轻松--异构法
雅思单词背诵:“少吃多餐”加“零敲碎打”
如何迅速记忆英语单词
雅思单词背诵小技巧
学英语方法浅谈--单词篇
雅思词汇如何过目不忘
如何用20天轻松攻克雅思单词
如何高效积累雅思词汇-听力篇
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |