【正文】 the drop calls for urgent attention. Oxygen levels in some tropical (熱帶的) regions have dropped by an astonishing 40 percent in the last 50 years, some recent studies reveal. Levels have dropped less significantly elsewhere, with an average loss of 2 percent globally.可知，對(duì)于科學(xué)家來(lái)說(shuō)，變暖的海洋正在失去氧氣并不奇怪，但這種下降的規(guī)模需要緊急關(guān)注。一些最近的研究表明，在過(guò)去的50年里，一些熱帶地區(qū)的氧氣含量下降了驚人的40%。其他地區(qū)的降幅較小，全球平均降幅為2%。所以根據(jù)前兩段，科學(xué)家最擔(dān)心的是變暖的海洋中日益惡化的脫氧現(xiàn)象。故選A。 （2）考查細(xì)節(jié)理解。根據(jù)第三段中的 as polar sea ice melts, it forms a layer of water above colder, more salty sea waters. This process creates a sort of lid that can keep currents from mixing surface water down to deeper depths. And because all oxygen enters the surface, less mixing means less of it at depth.可知，當(dāng)極地海冰融化時(shí)，它會(huì)在更冷、更咸的海水上形成一層水。這個(gè)過(guò)程會(huì)形成一種冰蓋，它可以防止水流將地表水混合到海洋更深的深度。因?yàn)樗械难鯕舛歼M(jìn)入了表面，所以較少的與海洋水的混合意味著更深的海洋含氧量更少。所以表面的極地冰水阻止氧氣下沉是海洋缺氧的原因之一。故選C。 （3）考查推理判斷。根據(jù)倒數(shù)第二段中的Ocean animals large and small, however, respond to even slight changes in oxygen by seeking refuge in higher oxygen zones or by adjusting behavior, Oschlies and others in his field have found. These adjustments can expose animals to new predators or force them into foodscarce regions. 可知，然而，Oschlies和他所在領(lǐng)域的其他人發(fā)現(xiàn)，無(wú)論大小，海洋動(dòng)物對(duì)氧氣的微小變化都有反應(yīng)，它們?cè)谳^高的含氧區(qū)尋求庇護(hù)，或是調(diào)整行為。這些調(diào)整可能使動(dòng)物暴露在新的掠食者面前，或迫使它們進(jìn)入食物匱乏的地區(qū)。所以海洋中氧含量減少迫使動(dòng)物離開(kāi)自己的棲息地，去氧氣含量較高的地區(qū)尋求庇護(hù)。故判斷出海洋脫氧改變了一些動(dòng)物的自然領(lǐng)地。故選A。 （4）考查主旨大意。通讀全文可知，短文說(shuō)明了海洋氧含量下降是一個(gè)與氣候變化有關(guān)的令人擔(dān)憂的趨勢(shì)，海洋氧含量下降的原因以及對(duì)海洋生物的影響和對(duì)其生存的威脅。所以短文主要是圍繞著海洋氧含量下降而展開(kāi)的。故短文的最佳標(biāo)題為海洋快喘不過(guò)氣來(lái)了符合題意。故選D。 【點(diǎn)評(píng)】本題考點(diǎn)涉及細(xì)節(jié)理解，推理判斷和主旨大意三個(gè)題型的考查，是一篇環(huán)保類閱讀，要求考生在捕捉細(xì)節(jié)信息的基礎(chǔ)上，進(jìn)一步根據(jù)上下文的邏輯關(guān)系，進(jìn)行分析，推理，概括和歸納，從而選出正確答案。7．Directions: Choose the one that fits best according to the information given in the passage you have just read. A tiny clue found in ancient deposits has unlocked big secrets about Greenland39。s past and future climate. Just beyond the northwest edge of the vast Greenland Ice Sheet, researchers have discovered lake mud that have survived the last ice age. The mud, and remains of mon flies in it, record two interglacial periods(間冰期)in northwest Greenland. Although researchers have long known these two periods—the early Holocene and Last Interglacial—experienced warming in the Arctic, the mix of fly species shows that Greenland was even warmer than previously thought. As far as we know, it has never been found in Greenland. We think this is the first time anyone has reported it in ancient deposits or modern lakes there, Axford said. We were really surprised to see how far north it migrated (遷徙). This new information could help researchers better measure Greenland39。s sensitivity to warming, by testing and improving models of climate and ice sheet behaviour. Those models could then improve predictions of how Greenland39。s ice sheet might respond to manmade global warming. After all, Greenland covers 80 per cent of the Arctic country and holds enough ice to equal 20 feet of global sea level. Northwest Greenland might feel really remote, but what happens to that ice sheet is going to matter to everyone in every coastal city around the world, said Yarrow Axford, an associate professor in the team. One of the big uncertainties in climate science is how fast the Earth changes when it gets warmer. Geology gives us an opportunity to see what happened when the Earth was warmer than today, said Axford. People might be surprised to see how today39。s Greenland looked during the last two interglacial periods. During the Last Interglacial, global sea levels increased by 15 to 30 feet, largely due to thinning of Greenland and Antarctica39。s ice sheets. However, now researchers believe northern Greenland39。s ice sheet experienced stronger warming than previously thought, which could mean that Greenland is more responsible for that sealevel rise. Finding lake deposits older than about 10,000 years, however, has been historically very difficult in Greenland. To measure these ancient temperatures, researchers look to ice cores (冰核) and lake deposits. Since ice and lake deposits form by a gradual buildup on annual layers of snow or mud, these cores contain history of the past. By looking through the layers, researchers can obtain climate clues from centuries ago.（1）Why are the remains of flies mentioned in the first two paragraphs? serve as evidence that there is still life in the Northwest Greenland. were one of the many ancient lives that were left in the Greenland mud. are indicators that Greenland was much warmer than previously thought. help the researchers realize that there was once a warm period in the Arctic.（2）The new information about Greenland is important because______________. have no idea how to measure Greenland39。s warming speed can help researchers better predict Greenland39。s response to warming should be more sensitive to the changes in the ice in Greenland is uncertain how fast the Earth changes with manmade global warming（3）Which of the following can be inferred from the passage? is easier for today39。s scientists to find ancient lake deposits. are surprised at the landscape feature of Greenland today. measure the changing temperatures by directly examining mud. holds enough ice that might one day threaten life in coastal cities.（4）Which do you think is the best title of the passage? Used to Be Much Greener Once Experienced Warm Periods Cities Warned of Coming Disasters Greenland, A Perfect Destination【答案】 （1）C（2）B（3）D（4）A 【解析】【分析】本文是一篇說(shuō)明文，介紹了在古代沉積物中發(fā)現(xiàn)的一條微小線索揭開(kāi)了格陵蘭島過(guò)去和未來(lái)氣候的大秘密。就在廣闊的格陵蘭冰原的西北邊緣，研究人員發(fā)現(xiàn)了在最后一個(gè)冰河時(shí)代幸存下來(lái)的湖泥。現(xiàn)在研究人員認(rèn)為，格陵蘭北部的冰蓋經(jīng)歷了比之前認(rèn)為的更強(qiáng)烈的變暖。 （1）考查推理判斷。根據(jù)第一段中的“The mud, and remains of mon flies in it, record two interglacial periods（間冰期）in northwest Greenland.”在格陵蘭島西北部，泥漿和常見(jiàn)蒼蠅的殘骸記錄了兩次間冰期；以及第二段中的“Although researchers have long known these two periods—the early Holocene and Last Interglacial—experienced warming in the Arctic, the mix of fly species shows that Greenland was even warmer than previously thought. ”盡管研究人員很早就知道這兩個(gè)時(shí)期——全新世早期和最后一次間冰期——在北極經(jīng)歷了變暖，但混合的蠅類表明格陵蘭島甚至比之前認(rèn)為的還要熱?？芍?，在前兩段中提到蒼蠅的殘骸是為了證明格陵蘭島的溫度比之前認(rèn)為的要高得多。故選C。 （2）考查細(xì)節(jié)理解。根據(jù)第三段中的“This new information could help researchers better measure Greenland39。s sensitivity to warming, by testing and improving models of climate and ice sheet behaviour. ”可知，這些新信息可以幫助研究人員更好地測(cè)量格陵蘭島對(duì)氣候變暖的敏感性。故選B。 （3）考查細(xì)節(jié)理解。根據(jù)第三段中的“Aft