-----Excuse me?

------  ____________________ .       

------How can I get to the nearest post office?

A．That’s OK.

B．Pardon?

C．What’s wrong?

D．Yes?

已知1 g氢气完全燃烧生成水蒸气时放出热量121kJ，且氧气中1 mol O=O键完全断裂时吸收热量496 kJ，水蒸气中1 mol H-O键形成时放出热量463kJ，则氢气中1 mol H-H键断裂时吸收热量为 [ ]

A.920kJ    

B.557 kJ    

C.436kJ    

D.188kJ