[问答题] 为什么说南极洲是一个冰原大陆？

The amount of LFG that may be loaded into a given tank is determined by（）. ["checking the loading sheet","loading to within 1 percent of outage","loading to within 10 percent of the safety relief valve setting","filling to the maximum level indicated on the liquid level gaging device"] Which of the following actions should be taken by the engine room watch when the general alarm is sounded continuously?（） ["The fire pump should be started","The boiler rims should be secured","The fixed CO_{2 <\/sub>system should be initiated into action","The engine room ventilation should be secured"] 下列组织的细胞中染色体数目与其体细胞染色体数目相等的是：（） ["甜菜的外胚乳细胞","荠菜的子叶细胞","百合的胚乳细胞","水杉的胚乳细胞"] 汉代察举制的主要科目有（）。 ["孝廉","贤良文学","茂才","方正","德才"] 以下四种汉字输入法中，（）不是中文Windows 2000预装的输入法。 ["智能ABC输入法","区位码输入法","郑码输入法","五笔字型输入法"] 为什么说南极洲是一个冰原大陆？}