---Why are you so late? ---I was on the

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问题选择题

---Why are you so late?

---I was on the way when it to me that I had left my book home,so I had to fetch it.[ ]

A. occurred

B. hit

C. happened

D. reminded

答案

答案：A

选择题

已知H₂(g) +1/2O₂(g)= H₂O(l) ΔH = -285.8 kJ·mol^-1。下列说法不正确的是 [ ]

A．H₂的燃烧热为285.8 kJ·mol^-1

B．2H₂(g) + O₂(g) = 2H₂O(l) ΔH = -571.6 kJ·mol^-1

C．1 mol H₂完全燃烧生成气态水放出的热量大于285.8 kJ

D．形成1 mol H₂O的化学键释放的总能量大于断裂1 mol H₂和0.5 mol O₂的化学键所吸收的总能量

单项选择题

美国议会从纵向对（）进行分权。

A.行政

B.司法

C.联邦和州

D.议会和两院制