题型:填空题 — His sudden death surprised his wife. — It was so bad. His wife was surprised ____ his death. [ ]A. by B. withC. at D. on 查看答案
题型:填空题 已知1 g氢气完全燃烧生成水蒸气时放出热量121 kJ,且氧气中1 mol O=O键完全断 裂时吸收热量496 kJ,氢气中1 mol H―H键断裂时吸收热量为436 kJ,求水蒸气中1 mol H―O键形成时放出热量A.463kJB.557 kJC. 486kJD.188 kJ 查看答案
题型:填空题 该图是某区域示意图,读图回答下列小题。关于该区域的叙述正确的是()A.①处河段水能资源丰富,是修建电站大坝的理想地点B.②处地貌由流水侵蚀作用形成C.该区域在6、7月份进入梅雨季节D.从③至④自然带的变化反映了垂直地域的差异 查看答案