生命与气候共同进化

①你能想到吗？亿万年以来，地球的气候在很大程度上是由地球的两大生命王国——动物界与植物界的斗争所决定的。动物吸进氧气而呼出二氧化碳，植物则吸进二氧化碳而放出氧气。二氧化碳为温室气体，因此可以立即得出结论：动物能使地球升温，而植物则使地球降温。如果哪一方占上风，那么地球就会面临温室效应或又一次严寒期。

②五亿多年前的“寒武纪大爆炸”时期，地球被各种各样的生物占领着，当时的土壤中到处都是把二氧化碳释放到空气中的节肢动物，使空气中的二氧化碳含量高达今天的20倍，当时的气候极其温暖。

③但是，植物很快进行了反击。化石显示，4.5亿年前，含有木质素的植物首次出现，木质素使细胞壁坚硬，这样植物就得以长大，地球上出现了第一批树木。随着全球的植物空前大量生长，毫无约束的光合作用从空气中吸取二氧化碳，使二氧化碳含量大大减少，而不能吸收木质素的、饥饿的节肢动物对此无能为力——地球进入了严寒期。

④动物再次通过进一步进化进行了回击。当时的主角是白蚁和恐龙，它们学会了如何食用木质素，如何繁荣昌盛。它们粗重的呼吸及对植被的破坏使空气中的二氧化碳高达今天的3倍，地球大部分地区酷热而潮湿，又恢复了温室效应。

⑤然而植物并没有被消灭。在6500万年前恐龙因为小行星的碰撞或其他灾难而彻底消失后，植物抓住了这一机会，突破点是第一批草地的出现。青草本身不会保存很多二氧化碳，但能形成软土，软土可以保存大量的二氧化碳，从而使空气中的二氧化碳含量降低。事实上，草地生态系统含有的碳比森林生态系统还多。 过去的4000万年来，大量草地布满全球，取代了许多年以前的森林地带。在草地的影响下，地球逐渐降温，终于在200万年前进入冰川期。

⑥大约1万年前，由于人类活动的显著增强，使地球空气的二氧化碳含量再度升高，尤其是近百年来，地球的温室效应愈来愈明显，全球气温升高。

⑦也许，地球上的整个生物圈就像我们所熟知的生物个体调节其体内环境那样，不停地调节着地球的大气环境，使气候能适合地球上生物生存进化的需要。换句话说，地球的生物圈是在主动地调节环境，而不是在被动地适应环境。果真如此，数十亿年的气候变迁不仅仅是太阳或地球的原因，生物为了自己的利益也深深地参与其中了。

小题1:阅读全文，说说影响地球气候的关键因素是什么？（3分）

小题2:本文是从哪三个方面说明生命与气候是共同进化的？（3分）

小题3:第⑥段中划线的词语能否删去，为什么？（3分）

大约1万年前，由于人类活动的显著增强，使地球空气的二氧化碳含量再度升高，尤其是近百年来，地球的温室效应愈来愈明显，全球气温升高。

小题4:地球是人类的家园，保护我们生存的环境已成为全球性问题。读完这篇文章，你从中得到哪些启示？请写出来。（60字左右）（6分）

       How do you get a man to do his share of the housework? If you are like most women, you’ve faced this question the hard way.

A man will enjoy a clean, orderly house, but he usually won’t make the effort to clean or organise it. This doesn't mean that a woman has to do all the housework:; she may have to manage many of the household duties, and request her partner’s participation（参与）. A woman can often say that men and women should take equal responsibility（责任） for housework.

Very few men are raised to be fully responsible for housework, and many men look on housework as women’s work. On the other hand, most men will readily work around the yard, make repairs and complete projects on weekends or evenings, and it’s important that you give your man appreciation for those things, too. Most men will take on a little additional housework around the house if asked politely. They are even more likely to do housework if they can choose what they want to do, and do it without being monitored.

Here’s the key: men want to feel that they are doing housework either because they want to do a task, or because they simply want to please their women. Men are much less likely to take on household tasks they consider uninteresting and unimportant. In other words, men are likely to do a household task just for the good of the house.

小题1: The passage is mainly about how to _____.

A．get men to take on some housework

B．get men to serve their families

C．praise men’ housework

D．make men do all the housework小题2:According to the passage, a man_____.

A．is willing to do housework

B．likes to be told to do housework

C．is taught to be responsible for housework from childhood

D．likes a clean house but doesn’t make efforts to clean it小题3:In order to get men to do some housework, women should often_____.

A．order them to do their share

B．ask them to do some housework politely

C．blame men’s laziness

D．monitor men’s work小题4:According to the passage, the underlined sentence in the last paragraph means that men won’t _____.

A．work without any payment

B．do unimportant household tasks

C．do housework without women’s praise

D．please their wives小题5: According to the passage, which of the following would a husband most probably like to do?

A．Cleaning the table.

B．Doing some sewing.

C．Painting the fence.

D．Asking his wife to work on the yard.