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

　　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