Part A
There are three reading passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the center.

If there is one thing scientists have to hear, it is that the is over. Raised on the belief of an endless voyage of discovery, they recoil (畏缩) from the suggestion that most of the best things have already been located. If they have, today’ s scientists can hope to contribute no more than a few grace notes to the symphony of science. A book to be published in Britain this week, The End of Science, argues persuasively that this is the case. Its author, John Horgan, is a senior writer for Scientific American magazine, who has interviewed many of today’s leading scientists and science philosophers. The shock of realizing that science might be over came to him, he says, when he was talking to Oxford mathematician and physicist Sir Roger Penrose. The End of Science provoked a wave of denunciation (谴责) in the United States last year. "The reaction has been one of complete shock and disbelief," Mr. Horgan says. The real question is whether any remaining unsolved problems, of which there are plenty, lend themselves to universal solutions. If they do not, then the focus of scientific discovery is already narrowing. Since the triumphs of the 1960s--the genetic code, plate tectonics (板块构造税), and the microwave background radiation that went a long way towards proving the Big Bang--genuine scientific revolutions have been scarce. More scientists are now alive, spending more money on research, than ever. Yet most of the great discoveries of the 19th and 20th centuries were made before the appearance of state sponsorship, when the scientific enterprise was a fraction of its present size. Were the scientists who made these discoveries brighter than today’s That seems unlikely. A far more reasonable explanation is that fundamental science has already entered a period of diminished returns. "Look, don’t get me wrong," says Mr. Horgan. "There are lots of important things still to study, and applied science and engineering can go on for ever. I hope we get a cure for cancer, and for mental disease, though there are few real signs of progress."

The term "the Big Bang" probably refers to ______ .