2017年公共英语考试五级考前精选模拟试题（2）
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本文导航第1页试题第2页答案解析 Section Ⅲ Reading Comprehension (50 minutes) Part A：Read the following texts and answer the questions which accompany them by choosing A，B，C or D.Mark your answers on ANSWER SHEET 1. Text 1 Gene therapy and gene based drugs are two ways we could benefit from Our growing mastery of genetic science. But there will be others as well.Here is one of the remarkable therapies on the cutting edge of genetic research that could make their way into mainstream medicine in the coming years. While it’S true that just about every cell in the body has the instructions to make a complete human，most of those instructions are inactivated，and with good reason：the last thing you want for your brain cells is to start churning out stomach acid or your nose to turn into a kidney.The only time cells truly have the potential to turn into any an all body parts is very early in a pregnancy.when so-called stem cells haven’t begun to specialize. Yet this untapped potential could be a terrific boon to medicine.Most diseases involve the death of healthy cells-brain cells in Alzheimer’s，cardiac cells in heart disease，pancreatic cells in diabetes，to name a few;if doctors could isolate stem cells，then direct their growth，they might be able to furnish patients with healthy replacement tissue. It was incredibly difficult，but last fall scientists at the University of Wisconsin managed to isolate stem cells and get them to grow into neural，gut，muscle and bone cells.The process still can’t be controlled，and may have unforeseen limitations;but if efforts to understand and master stem cell development prove successful，doctors will have a therapeutic tool of incredible power. The sanle applies to cloning，which is really just the other side of the coin.True cloning，as first shown with the sheep Dolly two years ago，involves taking a developed cel and reactivating the genome within，resetting its developmental instructions to a pristine state.Once that happens，the rejuvenated cell can develop into a full—fiedged animal，genetically identical to its parent. For agriculture.in which purely physical characteristics like milk production in a cow or low fat in a hog have real market value，biological carbon copies could become routine within a few years.This past year scientists have done for mice and cows what Ian Wilmut did for Dolly，and other creatures are bound to join the cloned menagerie in the coming year. Human cloning，on the other hand，may be technically feasible but legally and emotionally more difficult. Still，one day it will happen.The ability to reset body cells to a pristine，undeveloped state could give doctors exact： ly the same advantages they would get from stem cells：the potential to make healthy body tissues of all sorts，and. thus to cure disease.That could prove to be a true“miracle cure”. 51.The writer holds that the potential to make healthy body tissues will_____. [A]aggravate moral issues of human cloning [B]bring great benefits to human beings [C]help scientists decode body instructions [D]involve employing surgical instruments 52.The word“rejuvenated”(Para.5)most probably means_____. [A]modified [B]recoliccted [C]classified [D]reactivated 53.The research at the University of Wisconsin is mentioned to show_____. [A]the isolation of stem cells [B]the effects of gene therapies [C]the advantages of human cloning [D]the limitations of tissue replacepmnts 54.Which of the following is true according to the text? [A]The principle of gene therapy is applicable to that of cloning. [B]The isolation of stem ceils is too difficult to be feasible. [C]It is reasonable for all body instructions to be activated. [D]Cloned animals will eventually take control of the world. 55.Towards the genetic research，the author’s attitude can best be said to be that of_____. [A] frustration [B]indifference [C]amazement [D]opposition Section Ⅲ Reading Comprehension(共计35分。权重35%) Part A(每小题1分。共计l5分) 相关资料 |
