题目

下列事实与氢键有关的是 A．水结成冰体积膨胀，密度变小   B．水加热到很高的温度都难以分解 C．CH4、SiH4、GeH4、SnH4的熔点随相对分子质量的增大而升高 D．HF、HCl、HBr、HI的热稳定性依次减弱 答案：A________ the Great Wall, everyone considers it to be one of the wonders of the world. [　　] A．To speak of B．Speak of C．Speaking of D．Spoken of