The world's oceans have warmed 50 percent faster over the last 4

The world's oceans have warmed 50 percent faster over the last 40 years than previously thought due to climate change,Australian and US climate researchers reported Wednesday．Higher ocean temperatures expand the volume of water,contributing to a rise in sea levels that is covering small island nations and threatening to destroy the low-lying,densely-populated low regions around the globe. The study,published in the British journal Nature,adds to a growing scientific chorus of warnings about the pace and consequences rising oceans．It also serves as a corrective to a massive report issued last year by the Nobel-winning UN Intergovernmental Panel on Climate Change(IPC C),according to the authors. Rising sea levels are driven by two things:the thermal expansion of sea water,and additional water from melting sources of ice．Both processes are caused by global warming．The ice sheet that sits atop Greenland,for example,contains enough water to raise world ocean levels by seven meters,which would bury sea-level cities from Dhaka to Shanghai. Trying to figure out how much each of these factors contributes to rising sea levels is critically important to understanding climate change,and forecasting future temperature rises,scientists say．But up to now,there has been a puzzling gap between the projections of computer-based climate models,and the observations of scientists gathering data from the oceans. The new study,led by Catia Domingues of the Centre for Australian Weather and Climate Research,is the first to reunite the models with observed data．Using new techniques to assess ocean temperatures to a depth of 700 meters from 1961 to 2003,it shows that thermal warming contributed to a 0.53 millimeter-per-year rise in sea levels rather than the 0.32 mm rise reported by the IPC C. The rise in water levels is especially dangerous for small island nations and__.
A、low-lying urban areas
B、all coastal cities
C、people who live on the beach
D、Shanghai
【正确答案】：A
【题目解析】：从文中我们可以看到，海洋温度的升高会导致海平面的上升，进而覆盖小岛国和威胁到全球低洼、人口稠密的地区。特别是在提到“Low-lying,densely-populated low regions around the globe”时，明确指出了低洼且人口稠密的地区是受到威胁的。 现在，我们来分析给出的选项： A. low-lying urban areas（低洼的城区）：这与文中提到的“低洼、人口稠密的地区”相符。 B. all coastal cities（所有沿海城市）：文中并没有提到所有沿海城市都会受到威胁，只是强调了低洼和人口稠密的地区。 C. people who live on the beach（住在海滩上的人）：文中并没有特指海滩上的人会受到威胁，而是更广泛地提到了低洼地区。 D. Shanghai（上海）：上海作为具体的例子被用于说明，但如果我们仔细阅读原文，可以发现它只是作为一个例子来说明如果格陵兰岛上的冰盖融化，会淹没从达卡到上海这样的海平面城市，但并不意味着只有上海会受到影响。 综上所述，根据文章内容和逻辑分析，最符合题目要求的答案是A，即低洼的城区。