20．概要寫作．閱讀下面短文，根據(jù)其內容寫一篇60詞左右的內容概要．
With global warming and melting ice，it isn't easy being a polar bear anymore．Some studies have predicted that polar bears could die out by the end of the century．The good news is not all researchers think the bears are absolutely disappearing．Scientists at the American Museum of Natural History（AMNH） have published a new paper indicating that things might not be as bad for polar bears as some scientists expect．
To understand the reason for the researchers'cautious optimism，we must first understand the factors that are threatening the polar bear's existence．Polar bears consume a diet of mainly young seals．In order to hunt these seals，polar bears need to rest at the top of sea ice---the same ice that is increasingly melting for most of the year thanks to climate change．In another 50years，experts expect that the Arctic will be too warm for sea ice to form for half of the year，leaving polar bears without a reliable food source and in serious danger of starvation．
As it turns out，alternative food sources for the polar bears aren't completely out of the question．For as long as biologists have tailed after the animals，they've seen polar bears eating animals found on land like caribou（馴鹿） and snow geese---as well as the snow geese's eggs．
Can polar bears actually survive off these alternative food sources for long periods of time？To figure this out，researchers calculated the nutrients that a caribou and snow geese diet would provide．They found that even adult male polar bears would be able to obtain more calories than they would burn in hunting these meals．Moreover，the food would provide the food necessary to avoid starvation during the summer months．
Unfortunately，not all polar bears have tended to seek food on land．That said，the researchers expect that necessity would push more polar bears to hunt on land to avoid starvation．They also expect that the bears could learn from their fellow bears how to hunt on land until the practice becomes second nature．
分析 題目要求根據(jù)所給內容，寫一篇60詞左右的內容概要．題目主要考查學生把握文章主旨大意和段落大意的能力以及總結概括能力．熟練掌握從句、非謂語動詞等語法知識，對遣詞造句也有很大幫助．
亮點說明：參考答案的前兩句是對文章主旨大意的概括，后兩句是對第二三四段的總結．北極熊找到了新的食物，但并非所有的北極熊都會去陸地上捕獵．為了避免餓死，這是北極熊應該學會的．
高分句型一：
With global warming and melting ice，some scientists think that polar bears could die out by the end of the century．
隨著全球氣候變暖，冰川融化，一些科學家認為，到本世紀末北極熊可能消失．
高分句型二：
They have found polar bars have found alternative food sources and they can survive by hunting animals on land instead of your seals．
他們已經發(fā)現(xiàn)了北極熊找到替代的食物來源，與海豹不同的是他們可以通過狩獵動物生存在陸地上．
解答 With global warming and melting ice，some scientists think that polar bears could die out by the end of the century（高分句型一）．However，other scientists think that polar bears could die out by the end of the century．However，other scientists don't think so．They have found polar bars have found alternative food sources and they can survive by hunting animals on land instead of your seals（高分句型二）．The researchers expect all polar bears learn how to hunt on land to avoid starvation．
點評 英語寫作是一項主觀性較強的測試題．它不僅考查學生的寫作基礎而且還考查學生在寫作過程中綜合運用語言的能力．在撰寫時要注意主謂語一致，時態(tài)呼應，用詞貼切等．要提高英語寫作水平，需要兩方面的訓練：一是語言基礎方面的訓練，要有扎實的造句、翻譯等基本功，即用詞法、句法等知識造出正確無誤的句子；二是寫作知識和能力 方面的訓練以掌握寫作方面的基本方法和技巧．
