已知反应2H<sub>2</sub>O（g）=2H<sub>2</sub>（g）+O<sub>2</sub>（g）的平衡常数为，反应<img src="/Image1/a0/a005f91895b7457fb67848ff2b0b1524.jpg" />的平衡常数为，则反应（）<br>A:<img src="/Image1/86/8627bd4e7a5c95695e07d64721f678fa.jpg" /><br>B:<img src="/Image1/2d/2d18ab49e0c0590373fc63a336d1a55c.jpg" /><br>C:<img src="/Image1/6f/6fde12ad5766ca1db1ae796e73803d39.jpg" /><br>D:<img src="/Image1/6b/6b90769c8e4eb4d57e8b38fbed7d3d17.jpg" />