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海洋污染

    ①海洋污染通常是指人类活动改变了海洋原来的状态,使海洋生态系统遭到破坏。

    ②辽阔的海洋拥有巨量的海水,所以,尽管从远古到近代接纳了从陆地流入难以计数的各种物质,海洋却并没有发生重大变化。然而近几十年来,随着工业的发展,人类向海洋排放的有害物质越来越多。据报道,现在每年向海洋倾倒约600-1000万吨石油,1万吨汞,25万吨铜,390万吨锌,30万吨铅和100万吨有机氯农药。以致海洋局部环境急剧恶化,甚至发生了严重的海洋污染灾害。

    ③海洋污染的现状是:污染源多,污染范围广、程度严重。海洋污染主要包括石油污染、赤潮、毒物污染、塑料垃圾和核污染。目前海洋污染较严重的,就海域来看,有波罗的海、地中海、东京湾、美国纽约湾、墨西哥湾等;就国家来说,有日本、美国和西欧诸国。我国的渤海、黄海和南海的污染状况也相当严重,虽然汞、铜、铅的浓度大体尚在标准允许范围之内,但已有局部地区超过了规定标准。其中最严重的是渤海,有的鱼群死亡,渔场外迁;有的滩涂养殖场荒废;一些珍贵的海生资源正在丧失。

    ④海洋污染是怎样破坏海水环境的呢?海洋污染造成的海水浑浊严重影响海洋植物的光合作用,从而影响水体的生产力,进而危害鱼类;重金属和有毒有机化合物等,在海域中积累并通过海洋生物的富集作用,对以此为食的其他动物乃至人类造成毒害;石油污染在海洋表面形成广大的油膜,阻止空气中的氧气向海水中溶解,而且石油分解时还会消耗水中的溶解氧,造成海水缺氧,危害海洋生物;有机物污染会使海水富营养化,使海藻异常繁殖,赤潮泛滥,破坏生态平衡。

    ⑤现在,海洋污染已经引起国际社会越来越多的重视。

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    In summer, it's common on the street to see many Chinese women holding parasols1 to protect themselves from the sun.  But when Amy, an exchange student in Beijing from the US, first saw this, she found it strange, even impossible to understand.  She wrote on her blog, "Unlike Chinese women, American women like to put on their tank tops and sunglasses during summer. If you walk around an American college campus2, you will probably see girls out on the grassy fields reading, but they really hope to get a head start on their summer tan3."

    This may be caused by the different standards of beauty between the US and China. Many Americans don't want white skin. They would rather be tanned3. Amy also wrote, "Having darker skin is so popular that many women and men will pay for fake4 tans so that they can keep their sun-kissed appearance during the winter months, too."

    Why do they like tanned skin? Michelle Louis reported in her research, "The process of tanning can help make people's skin smooth and hide marks." She further explained, "Tans make people's skin appear healthier and make them appear thinner than when they have pale skin."

    Perhaps there is no real ideal standard of beauty. In different cultures and at different times of history, the standards change. On Amy's blog, she also gave two examples: Some women carried parasols around trying to keep their white skin in the US 150 years ago; During the Tang Dynasty in China, heavy women were thought attractive. But now, Chinese women prefer to be slim.

    In a word, different standards of beauty should be respected. People may grow up with only one idea of what beauty is, but it doesn't mean that it's necessarily the correct or the best idea.

New words:

①parasol n. umbrella used to protect people from the sun 阳伞

②campus n. grounds of school, college or university校园

③tan n. the brown colour of sun-kissed skin 晒成的棕褐

④become brown by the sun 晒成棕褐色,晒黑

⑤fake adj. not real 假的