未知题型 At the bottom of the world lines a mighty continent still wrapped in the Ice Age and, 31 recent times, unknown to man. 32 of the continent is a complete blank on our maps, A 1,000-mile stretch of the coastline has never been 33 by a ship. Man has explored, on foot, less than one per cent of its area. Antarctica differs fundamentally 34 the Arctic regions. The Arctic is an ocean, covered with d 35 ice and surrounded by the land masses of Europe, Asia, and North America. The Antarctic is a continent almost as large as Europe and Australia c 36 , centered roughly on the South Pole and surrounded by the most u 37 water areas of the world—the Atlantic, Pacific, and Indian Oceans. The continental ice sheet is more than two miles 38 in its center; thus the air over the Antarctic is much colder than it is 39 the Arctic regions. More than a million persons live within 2,000 miles of the North Pole in an area that includes most of Alaska, Siberia, and Scandinavia—a region rich 40 forest and mining industries. Apart from a handful weather stations, within the same distance of the South Pole is not a single tree, industry or settlement.

单项选择题 A相对其客户以支票结算， 则其应满足如下条件：（ ）。

单项选择题 初期清扫有几个步骤（）