A. may be inhabited by attractive Martians B. may have some vegetable life C. can have no life at all D. may have both vegetable and animal life 参考答案:B 答案解析:文章第二段最后一句说:Mars with a very thin atmosphere and a severe shortage of water,may well support simple p
第23题: [单项选择]下列哪项不是腰痛的主要病因() A. 感受寒湿 B. 感受湿热 C. 劳倦过度 D. 情志内伤 E. 跌打损伤 参考答案:D
第24题: [填空题]There are three components needed for ignition and combustion to occur: fuel, air and ______. 参考答案:a heat source 答案解析:[解析] 此题为细节题。题目涉及的是three components needed for ignition and combustion(点燃和燃烧的三要素)。由此可将目标锁定在此句中:There