职称英语理工类AB级阅读理解复习必备训练题(3)

　　Scientists have long understood that supermasvive black holes weighing. Millions or billions of suns can tear apart stars that come too close. The black holegravity pulls harder on the neatest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. 　　When the star gets Close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would he complicated by shock waves generated during the flattening process and that not nuclear explosion should occur. 　　The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays. 　　Brassart aggress. Perhaps it can be observed in the X-rays and gamma rays, but its something that needs to be more studied,he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Almos, New Mexico, US, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case they exploded in the process. 　　A the black hole could tear apart the star 　　C the black hole could dwindle its size considerably 　　2. According to the third paragraph, researchers differed from each other in the problem of 　　B whether the stars would increase its density and temperature 　　D whether the uneven forces would flatten the stars 　　A No nuclear explosion would be triggered inside the star 　　C. Much of the stars matter thrown by the explosion would be beyond the black holes reach 　　4. What will happen several months after the explosion of the star? 　　B the black holes matter will heat up 　　D the black holes matter will release ultraviolet light and X-rays