Changes in climate that had already taken place are manifested __1__ from the decrease in extent and thickness of Arctic sea ice, perma- __2__ frost thawing, coastal erosion, changes in ice sheets and ice shelves, altered distribution and abundance of species. __3__ Nowadays snows melt earlier in the springtime. Lakes, rivers and bogs freeze much more later in the autumn. Reindeer herding __4__ becomes more difficult so the ice is weak and may give way. __5__ Nowadays winters are much colder than they used to be. __6__ Occasionally during winter time it rains. We never expected this;we could not be ready for this. It is very strange. The cycle of the yearly calendar has been disturbed greatly. Warming over northern land areas has been very greater than elsewhere in the world. The __7__ changes are due to human modification of the concentration of greenhouse gases during the 20th century, leading quite directly to the projections the Artic will warm by several times as much during the __8__ 21st century as it did during the 20th century. The amplified warming in Arctic, in turn, directly contributes to overall global warming, as __9__ well as cause changes that create impacts over the rest of the globe. __10__

　　答案：

　　1.had-have。这里没有语境表明这个动作或者状态发生在过去某个时间点以前，所以用过去完成体不合适。

　　2.from-in。manifest something in something 意思是“在……方面表现出来”。例如：His frustration manifested itself in his silence and inactiveness。

　　3.^altered-and。这里要看出并列的几个名次词组是 extend and thickness…、permafrost thawing、coastal erosion、changes in ice sheets and ice shelves、altered distribution and abundance of species，三个斜体的and并不是连接这几个并列项的，所以必须在最后一项altered distribution and abundance of species前加上并列连词and。

　　4.more-/。later本身已经是比较级，不用再加more。

　　5.so-as/since。这里要理清主从句的因果关系，从上下文看，应该说“冰层变薄”是因，“放牧驯鹿变得困难”是果，所以应该把so 改成as或since。

　　6.colder-warmer。文章谈的是气候变暖问题。“冬季变冷”显然是与整个文章的逻辑不符。

　　7.very-/。very不修饰形容词或者副词的比较级。(觉得这里把very 改为much 也没问题)

　　8.projections^-that。projections后面的从句是同位语从句，同位语从句的引导词that不可以省略。

　　9.^Arctic-the。“北极”Arctic前要加定冠词。

　　10.cause-causing。as well as相当于介词，其后不直接跟动词，应该是名次或动词-ing分词

　　Cities can be frightened places. The majority of the population live in noisy massive tower blocks. __11__

　　The sense of belonging to a community tends to appear when you live thirty floors up in a skyscraper. __12__

　　Strange enough, whereas in the past the inhabitants of one street all knew each other, __13__

　　nowadays people on the same floor in tower blocks even say hello to each other. __14__

　　Country life, on the other hand, differs from this kind of isolated existence in that a sense of community generally keep the inhabitants of a small village together. __15__

　　People have the advantage of knowing that there is always someone to turn to when they need help.

　　So country life has disadvantages too. For example, shopping becomes a major problem and __16__for anything slightly out of the ordinary you have to go for an expedition to the nearest large town. __17__

　　The country has the　advantage of peaceful and quiet, but suffers from the is advantages of being cut off. __18__

　　The city has noise and population which do harm to human health. But one of　their main advantages is that __19__ you are at the centre of things and that life doesn’t come to an end even at ten at night. Some people have found a compromise be-tween the two: they expressed their preference for the　quiet life by leaving for the city and moving to the __20__country within commuting distance of the large city.

　　答案：

　　11.把frightened改为frightening。frightened是“受到惊吓的”，表明心理状态，而frightening表示“令人害怕的”，表示事物性质。

　　12.把appear改为disappear。“当你住在摩天大厦的三十层里”，可以推测这里要表达的是归属感的消失，而不是产生归属感。

　　13.把Strange改为Strangely。Strangely enough，是固定短语，经常用作插入语，意思是“说也奇怪，最奇怪的是”。

　　14.在say前面加上don’t。此处说的是，现在住在同一层楼的人甚至见面都不打招呼。

　　15.把keep改为keeps。in that 引导的句子主语应该是 a sense，故谓语应为单数。本句的意思是，农村生活与这种隔绝孤立的生活不同，因为一种归属感把小村里的居民联系在一起。

　　16.把so 改为but/yet。上文提到了乡村生活的好处，下文是转折，要用but或者yet。

　　17.把for改为on。“去远征”应该用go on a expedition，而go for 的意思是“去找，努力获取，拥护”。

　　18.把peaceful改为peace。of 后面不应该用形容词，所以应该改为peace。这里需要注意的是quiet既是名词又是形容词，不要被迷惑。

　　19.把their改为its。此处的代词应该指代上文的 the city。

　　20.删除leaving后面的for，或者把for改为from。leave表示“离开某地”，而leave for表示“离开某地去另外一个地方”，for后面接的是目的地。本句说的是离开城市，搬到乡村，所以for是多余的。