问题 解答题

10、地球现存已发现和未发现的生物物种估计有一千多万种,其各自独特的基因是在30亿年地球生命进化过程中形成的.天然的生物基因库对人类是一个巨大的宝藏,是一笔难以估量的财富,它也维系着人类自身的命运.然而令人堪忧的是:我们现在还能守住天然生物基因库这个地球上最后的一片“净土”吗?

我们必须面对这样一个事实,即现在已经大面积推广的基因工程作物并不理想,还必须改进.既然我们完全可以做得更好,那为什么现在要急于求成呢?而急于求成,则有可能会使人类付出巨大的代价.

一种新事物的出现,当看到它带来巨大利益时,人们往往蜂拥而至,一哄而上.但任何见利忘义或短视的行为,带来的都是灾难,这样的教训实在太多了.如果我们不备加注意维护周围环境中天然生物基因库的纯净,那无异是在自毁家园.

查阅相关资料,说说我们能守住最后一片“净土”吗?

要点:转基因技术是科技进步和人类文明高度发达的产物,圆满地解决转基因技术的安全性问题,是人类社会奉献给21世纪的最珍贵礼物.

答案

转基因生物技术在很大程度上能对农业生产产生很大的促动,但是任何事物都有其两面性,现代生物技术可以将无关联的生物品种,包括植物、动物和微生物中的遗传材料相互转移(并且可以指定要转移的基因),产生出新型的植物、动物和微生物.因此技术本身还是存在一些不能确证但却危害巨大的隐患,包括对生态环境和公众健康的威胁.在生态方面,如果转基因作物的外源基因向亲缘野生种转移,就会污染到整个种子资源基因库转基因技术他们正在积极研究许多对策.人类的聪明才智使我们有信心认为:基因工程生物的安全问题终究是可以得到基本解决的.

不管怎样,必须强调指出的是,以基因工程为代表的生物技术革命很可能是解决全球粮食问题的最佳选择.很可能在不远的将来,我们吃的、穿的大都是基因工程产品,就像今天我们吃的、穿的是经过驯化、改造过的动植物产品一样

故答案为:人类的聪明才智使我们有信心认为:基因工程生物的安全问题终究是可以得到基本解决的.

不管怎样,必须强调指出的是,以基因工程为代表的生物技术革命很可能是解决全球粮食问题的最佳选择.很可能在不远的将来,我们吃的、穿的大都是基因工程产品,就像今天我们吃的、穿的是经过驯化、改造过的动植物产品一样.

单项选择题
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根据短文内容, 从短文后的选项中选出能填入空白处的最佳选项, 选项中有两项为多余选项.

       Do you know how to be a street smart? Being street smart means knowing how to keep yourself

safe from strangers when you're alone or with other kids.     1      

    Most strangers aren't dangerous and wouldn't do anything to hurt kids. Unfortunately, though. some

strangers can be dangerous, and it's impossible to tell who'ok and who's not.     2    That's why it's

important to follow these safety rules all the time:

    Make your whereabouts known.

    The adults who are taking care of you need to know where you are and when you'll be coming home. 

        3    

    It's more fun and safer to do things with friends. Traveling with afriend whenever you can is a good

idea, and traveling with a group of kids is even better. 

       4   

    Safe spots are places where you can stop if you need help. Like the houses of kids you know, the

houses of your parents'friends, police stations, libraries, and fire departments. When you're walking or

riding your bike, make a mental note of the safe spots along your route. That way, you'll know where

they are in case you ever need one. 

        5    

    You're probably been told lots of times that you should not shout and keep quiet. But when you think

you might be in danger, it'a the perfect time to be noisy! If a stranger gets close to you, follows you or

tries to grab you, shout as loudly as you can and try to get away. People in the area will hear what's

going on and help you, so make plenty of noise.

    A. Stick with a friend.

    B. Pick out safe spots.

    C. It helps you stay safe.

    D. Shout"help"when necessary.

    E. Go to school with your friends.

    F. Make much noise if you are in danger

    G. A dangerous person doesn't necessarily look scary.