问题 阅读理解

B

You're in a bit of a dilemma standing in front of the produce section of your local supermarket. In one hand, you're holding a conventionally grown Granny Smith apple.In your other hand, you have one that's been organically grown. Both apples are firm,shiny and green. Both provide vitamins and fiber, and both are free of fat, sodium and cholesterol.

The conventionally grown apple costs less and is a proven family favorite. But the organic apple has a label that says "USDA Organic". Does that mean it's better? Safer? More nutritious? Several differences between organic and non-organic foods exist. Become a better informed consumer for your next trip to the supermarket.

The word "organic" refers to the way farmers grow and process agricultural products, such as fruits, vegetables, grains, dairy products and meat. Organic farming practices are designed to encourage soil and water conservation and reduce pollution.Farmers who grow organic produce and meat don't use conventional methods to fertilize, control weeds or prevent livestock disease.

Here are other differences between conventional fanning and organic farming:

* Organic or not? Check the label.

The U.S. Department of Agriculture (USDA) has established an organic certification program that requires all organic foods to meet strict government standards. These standards regulate how such foods are grown, handled and processed.Any farmer or food manufacturer who labels and sells a product as organic must be USDA certified as meeting these standards. Only producers who sell less than $5,000 a year in organic foods are exempt (免除) from this certification.

If a food bears a USDA Organic label, it means it's produced and processed according to the USDA standards. The seal is voluntary, but many organic producers

use it.

46. The main purpose of the passage is_________.

A. to promote the sales of organic food

B. to inform people organic food is better for their health

C. to persuade people to become informed consumers

D. to compare conventional and organic foods

47. According to the passage, organic farming is intended to_________.

A. improve the quality of the soil and water

B. take the place of the traditional agriculture entirely

C. adopt eco-friendly methods to grow plants and feed animals

D. prevent livestock from getting disease more effectively

48. According to the passage, the conventionally grown apple_________.

A. costs less but tastes worse than an organic one

B. doesn't look the same as an organic one

C. has proven itself acceptable by the family

D. contains more fat, sodium and cholesterol

49. Which of the following methods belongs to organic farming?

A. Using chemicals to kill insects and prevent disease.

B. Using rotted plants as fertilizer to promote plant growth.

C. Using growth hormones to speed up animals' growth.

D. Using pests to reduce insects and disease.

50. From the passage we know the organic certification program________.

A. is not meant for all producers of produce

B. makes it compulsory to attach a USDA Organic label

C. sets restrictions on the sales of organic produce

D. requires all foods to satisfy the strict government standards

答案

46---50  DCCBA  

阅读理解与欣赏

“FE复合酶”——划时代的高科技成果(10分)

①消炎抗菌.以后很可能不再用抗生素,而用酶这种全无毒副作用的生物素。

②鸡没有牙齿,却能将硬如米粒的食物磨得粉碎。是什么物质有如此大的功力?是酶。它包含在鸡肫内壁那层黄膜之中,为此,这层黄膜也成为珍贵的药材。

③酶的作用和种类很多,提取却极为复杂,因而贵比黄金。

④酶能够溶解细菌,称为“溶菌”,是本世纪的一个重大发现。而将酶应用于抗菌消毒领域,并证明它比抗生素能更好地担负起对付细菌感染的重任,则是一个划时代的成果。

⑤本世纪三四十年代,在抗生素未被发现之前,细菌感染是威胁人类生命的最重要因素之一。当青霉素、链霉素类药物等相继问世后,人类平均寿命提高了几十年。然而,随之而来的是一个新的严峻问题:耐药菌出现了。这使得抗生素的剂量越用越大,效果却越来越差。据美国媒体报道,因耐药菌感染,仅延长住院时间和必须使用昂贵的新型抗生素两项,每年就要增加300亿美元的开支。不仅如此,抗生素引起的毒副作用和不良反应也令人吃惊和震撼。据《健康报》报道,我国每年因药物不良反应死亡的有19.2万人,住院的有250万人。有人担忧,这样下去我们的后代会不会遭遇一个瘟疫横行却无药可治的悲惨世界。

⑥奇迹就在此时出现,有人在葡萄球菌之中发现了“溶菌酶”。试验证明,它能有效溶解革兰氏阳性菌,尤其对世界医学界都极为棘手的耐药性金黄色葡萄球菌效果显著。随后,世界各地的科学家都展开了对它的研究。1987年,我国复旦大学生命科学院通过基因克隆方法从安全菌中获得了溶菌酶,以复旦(FUDAN)和酶(ENZYME)英文的第一个字母而命名“FE”(复旦酶)。FE酶及FE复合蛋白酶制剂被认定为划时代的高科技成果。

⑦实践证明,FE及其复合酶制剂确是非常优良的抗菌荆。它的杀菌机理非常独特,不是简单地在细菌细胞壁上形成屏障,而是通过直接裂解菌体细胞壁,彻底杀死细菌,因而不产生耐药性。作为本质为蛋白质,能随人体新陈代谢而排泄的纯生物制剂,它还具有无任何毒副作用的特点。它使得抗生素带来的耐药性和毒副作用两大难题迎刃而解。以FE技术相继开发出用于治疗烧伤、外科手术后期耐药菌感染的FE复合酶消毒剂,可广泛用于手术、器械、餐具等消毒的FE复合醇消毒剂(Ⅱ)、用于治疗咽喉炎、口腔溃疡、牙龈炎等的牙膏、口腔喷雾剂等口腔护理用品。其中FE复合酶消毒剂成为目前惟一获得卫生部批准的生物型消毒剂。

小题1:.什么是酶?根据选文的相关内容给“酶”下定义。(2分)

                                                                                                                                              

小题2:.第5段主要使用了哪些说明方法?具体说出使用这些说明方法的作用。(4分)

                                                                                                                                              

小题3:.根据选文信息,说说“溶菌酶”的发现有何重大意义?(2分)

                                                                                                                                              

小题4:.为什么说FE复合酶的开发是“划时代的高科技成果”?(2分)

                                                                                                                                              

单项选择题