問題詳情


(B)Most polar bears inhabit the Arctic and around the North Pole. They thrive in theseArctic conditions because this is where their food sources are, and their bodies are made tohandle the harsh Arctic conditions. Polar bears spend ____(21)____ of their time in the ArcticOcean hunting and searching for food. In the winter months they walk on the ice and look forseals and in the summer months they wait on the shore for them. Polar bears know how to   use the climate and the land conditions to their benefit when hunting for seals. They will walkon an ice floe (a sheet of floating ice) and look for holes or cracks in the ice. ____(22)____breathe at some time, polar bears wait there for a seal to come up for a breath. Polar bearsneed the ice to live. They hunt seals from the ice floes. They have to have enough fat storagebuilt up throughout the winter to last them throughout the spring, summer, and parts of fall.The temperatures that the polar bears have to endure in the winter can range from -40°Fto as cold as -90°F.        The summer months can be much warmer for the polar bears withtemperatures ____(23)____ to 77°F. Scientists who have been working in the polar and arcticregions have taken ice core samples from deep within the snow and ice that cover the northernpole. They have made ____(24)____ discoveries. The carbon dioxide levels have neverbefore, over the last ten thousand years, got to 300 parts per million (ppm). However, withinthe last few decades the carbon dioxide level has not only got to 300 ppm ____(25)____surpassed it greatly. What does that mean? It means that the earth now has more carbondioxide, the greenhouse gases, ____(26)____ allowing as much heat from the sun to go back intospace. The greenhouse gases hold this heat back; ____(27)____, the temperature of the earthis getting higher.       If this warming trend continues, in about 50 years the earth will be so warm that the PolarRegions, the regions that the polar bears depend on for survival, will not exist. When there islittle ice and little snow left, polar bears will not be able to survive in the wild. They will belikely to become ____(28)____ someday in the future. Then, ____(29)____ they may existwould be in zoos. Climate change is ____(30)____ on the polar bears already. So to answerthe question, is global warming killing the polar bears? Yes, and we have to begin acting nowto help with their survival.
21. Choose the wrong one.
(A) plenty
(B) a good deal
(C) large quantities
(D) a great number

參考答案

答案：D
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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