Section A

　　47. Apollo program

　　48. monsters

　　49. 7,000

　　50. It may free humanity from the terrible scourge of diverse diseases./It may reduce people's suffering from some terrible diseases.

　　51. He wants to show that from past experience humans may not use the new knowledge wisely.

　　Section A

　　47.文章一开始就讲到了人类基因工程规模浩大。从第二段第二句“Costing more than ￡2billion，it is the most ambitious scientific project since the Apollo program that landed a man on the moon.”可知，自阿波罗登月计划以来，基因工程是最具有“雄心壮志”的科学研究项目。可见作者通过比较人类基因组工程和阿波罗登月计划，向读者揭示该工程的规模。因此，正确答案为“Apollo program”。

　　48.第二段最后一句“But others see the future through a darker glass and fear that the project may open the door to a world peopled by Frankenstein's monsters and disfigured by a new eugenics.”中的弗朗肯斯坦的怪物出自19世纪英国著名小说家玛丽·雪莱的科幻小说《弗朗肯斯坦》，其中讲述生物学家弗朗肯斯坦创造了一个面目可憎、奇丑无比的怪物，最终被其杀死的故事。可见有人担心基因组工程一旦解开人类基因的全部秘密，最终毁灭缔造者的基因怪兽可能会由此产生。因此，本题正确答案为“monsters”。

　　49.第三段第三、四句“Witten out along the double helix of DNA are the chemical letters of the genetic text，for the human genome contains more than 3 billion letters.On the printed page it would fill about 7，000 volumes.”中的volume指“一册书、一卷书”。由此可知正确答案是“7，000”。

　　50.第二段第三句“Those working on the Human Genome Project claim that the new genetic anatomy will transform medicine and reduce human suffering in the 21st century.”和第四段第一句“If properly applied，the new knowledge generated by the Human Genome Project may free humanity from the terrible scourge of diverse diseases.”都提到如果合理应用该工程的研究结果，人类可以免受很多可怕的疾病的折磨。由此可见，本题可以回答为“It may free humanity from the terrible scourge of diverse diseases./It may reduce people's suffering from some terrible diseases.”。

　　51.最后一段第二句作者提到如果不能明智地运用基因组工程带来的新知识，就有产生新的歧视和新的压迫的危险(But if the new knowledge is not used wisely，it also holds the threat of creating new forms of discrimination and new methods of oppression.)。随后作者提到了原子能的发现，并说明掌握原子能改变了国家的命运，也给我们的生活蒙上了阴影。作者由此表达了自己的担心，即基因组工程如果不能被人类明智使用，也会给人类带来无尽的威胁。因此，本题答案可以归纳为“He wants to show that from past experience humans may not use the new knowledge wisely.”。