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