夹层玻璃既是具有较高的热反射能力、又能保持良好的透光性能的平板玻璃，又称镀膜玻璃。( )
参考答案：错
Do I need _______ a dinner for the honored guests? Yes, you need _____ something special for them. [ ]
A. prepare for; cook
B. prepare; to cook
C. to prepare; to cook
D. to prepare for; cook
A．声音的传播速度不断减小
B．声音的频率不断减小
C．声音的振幅不断减小
D．声音的音调不断降低
