Eta Carinae 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 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. 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 can pass through this cloud, so telescopes that receive these wavelengths can observe what is occurring. Eta Carinae has other unique features, and is the only star known to produce an ultravioletlaser that is brighter than that produced by the Sun. Lasers have been observed in other frequencies from a few stars. A. some very common behaviour B. some very dull behaviour 32. The word period in Paragraph 3 means the length of time B. for which Eta carinaes brightening lasts. D. it takes the laser from Eta carinae to travel to the earth. A. it is too far away. B. there is too much dust and gas around it. 34. Astronomers are particularly interested in Eta Carinae because C. it exploded in 1987. D. it is brighter than the sun. A. It will end up as a supernova.mda.com C. It is the only star that sends out an ultraviolet laser. Answers: 31. D 32. A 33. B 34. A 35. C
上一篇: 职称英语综合类阅读理解练习(7)
2016春冀教版英语七下Unit 4《Lesson 20 Join Our Club》ppt课件1
2016春冀教版英语七下Unit 4《Lesson 19 A Dinner Date》ppt课件1
2016春冀教版英语七下Unit 3《School Life》ppt单元复习课件
2016春冀教版英语七下Unit 4《Lesson 23 A Weekend with Grandma》ppt课件1
2016春冀教版英语七下Unit 4《Lesson 20 Join Our Club》ppt课件
2016春冀教版英语七下Unit 6《Lesson 31 What Strange Weather》ppt课件
2016春冀教版英语七下Unit 4《Lesson 21 What Is Your Club Type》ppt精品课件
2016春冀教版英语七下Unit 4《Lesson 24 How was Your Weekend》ppt课件
2016春冀教版英语七下Unit 2《Lesson 11 Food in China》ppt课件
2016春冀教版英语七下Unit 6《Lesson 33 Kim’s Favourite Season》ppt课件
2016春冀教版英语七下Unit 6《Lesson 33 Kim’s Favourite Season》ppt精品课件
2016春冀教版英语七下Unit 2《Lesson 11 Food in China》ppt精品课件
2016春冀教版英语七下Unit 2《Lesson 10 Music and Dance》ppt课件1
2016春冀教版英语七下Unit 3《Lesson 18 Teaching in China》ppt课件2
2016春冀教版英语七下Unit 4《Lesson 19 A Dinner Date》ppt精品课件
2016春冀教版英语七下Unit 6《Seasons》ppt单元复习课件
2016春冀教版英语七下Unit 4《Lesson 22 Big Plans for the Weekend》ppt精品课件
2016春冀教版英语七下Unit 6《Lesson 32 I Can’t Wait for Winter》ppt课件
2016春冀教版英语七下Unit 4《Lesson 23 A Weekend with Grandma》ppt课件
2016春冀教版英语七下Unit 2《Lesson 7 What’s Your Project about》ppt精品课件
2016春冀教版英语七下Unit 2《Lesson 10 Music and Dance》ppt课件
2016春冀教版英语七下Unit 4《Lesson 22 Big Plans for the Weekend》ppt课件
2016春冀教版英语七下Unit 4《Lesson 21 What Is Your Club Type》ppt课件1
2016春冀教版英语七下Unit 6《Lesson 36 Spring in China》ppt精品课件
2016春冀教版英语七下Unit 2《Lesson 12 A Blog about the Silk Road》ppt精品课件
2016春冀教版英语七下Unit 7《Lesson 37 You Are What You Eat》ppt课件
2016春冀教版英语七下Unit 6《Lesson 35 Surfing in Sydney》ppt课件
2016春冀教版英语七下Unit 6《Lesson 34 Steven’s Report》ppt精品课件
2016春冀教版英语七下Unit 4《Lesson 22 Big Plans for the Weekend》ppt课件1
2016春冀教版英语七下Unit 7《Lesson 37 You Are What You Eat》ppt课件1