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如图是1949年至1990年我国人口、粮食产量、人均粮食占有量增长趋势图,读图,完成下列各题。

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同类题1

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    目前,海洋的污染正在日趋加剧,其中海洋的石油污染尤为严重。由于石油在工业化中的重要作用,以及全球石油分布的严重不均衡性,使石油的运输显得格外重要;由于大型油轮的营运成本较低,而经济效益却很高,因此在现代技术所能达到的范围内,建造的油轮吨位越来越大,往往在20万吨以上。目前,世界所需石油的2/3经海路运输,经常运行在航道上的油轮大约有7 000艘之多。大型油轮失事以后,其中的原油部分或全部流入海洋中,从而造成严重的海洋石油污染。此外近海采油平台及输油管的石油泄漏事故,也是造成海洋石油污染的重要原因,这些海洋石油污染给海洋生态带来严重危害。

    石油溢出后,使污染区内的甲壳类和鱼类迅速死亡,海鸟也难以幸免。因为原油能损害羽毛的功能,使海鸟体温降低,其游泳和飞翔能力降低,最后冻饿而死。据统计,每年死于石油污染的海鸟多达数十万只,而甲壳类和鱼类根本无法统计。

    不透明的油膜降低了光的通透性,使污染海域藻类的光合作用受到严重影响,其结果一方面使海洋产氧量减少;另一方面,藻类生长不良也影响和制约了海洋动物的生长和繁殖,从而对整个海洋生态系统发生影响。

    海面浮油内的一些有毒物质会进入海洋生物的食物链,据分析,污染海域的鱼虾及甲壳类致癌物浓度明显增高。海面浮油还可萃取分散于海水中的氯烃,如DDT、毒杀芬等农药和聚氯联苯等,并把这些毒物浓集到海水表层,对浮游生物、甲壳类动物和晚上浮上海面活动的鱼苗产生有害影响,甚至直接触杀。

    石油一旦泄漏而流入海洋后应及时采取的措施,目前主要仍是采用围栏将海洋表面的泄油围住,以避免再进一步大面积地扩展,然后要尽快地用清污船将石油收集起来。

    进入海洋的石油,一部分可直接挥发而进入空气;一部分受紫外线作用可发生光极慢的化学分解,而绝大部分石油污染都要依靠微生物的降解作用来净化。能降解石油的微生物种类很多,目前已经知道细菌、放线菌、真菌中有70个属,约200多个种能氧化降解石油。在近海、海湾等处,因海水含有丰富的N、P等营养物质,石油降解菌的数量较多,石油流入此海域后,较容易被氧化分解掉。然而,由于外海洋水中N、P等营养物质的缺乏,石油降解菌的增殖受到制约,那里的石油降解菌很少,一旦污染,很不容易很快消除。

同类题4

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    Maybe you have heard the expression “When in Rome, do as the Romans do”. So when you want to do business in France, you have to get to know French culture, to make marketing plans, and to run your business by local laws.

    ____The French take great pride in their language, so anyone who does not speak it may run the risk of being disrespected by his French colleagues or business partners. Also, another reason why learning French is important is that it is a great way to show every possible French business partner that you care and respect their country's culture and language.

    The first thing that you should do when meeting someone new is to shake his hand firmly and always look the person in the eye. In social meetings with friends, kissing is common.

    Use first names only after being invited to.____ The French will sometimes introduce themselves using their surname first, followed by their first name.

    Dress well.____ Your business clothing is a reflection of your success and social status. Always try to be tasteful and stylish. Women are advised to dress simply but elegantly.

    The French are passionate about food, so lunches are common in doing business m France, which usually consist of an appetizer, main meal with wine, cheese, dessert and coffee, and normally take up to two hours.____.

    Do not begin eating until the host says, “bon appetite”. Pass dishes to the left, keep wrists above the table and try to eat everything on the plate.____ This may suggest that you find the food tasteless.

A. The French draw information about people based on their appearance.

B. This is a time for relationship building.

C. Wearing make-up is practiced widely by business women.

D. Language should be the focus of anyone planning to do business in France.

E. Be careful with adding salt, pepper or sauces to your food.

F. Use Monsieur or Madame before the surname.

G. If eating in a restaurant, the person who invites always pays.