The piezoelectric material in the transducer:探头压电材料是:

A、converts electrical energy into soun.转化电能到声能
B、converts electrical energy into mechanical energy and mechanical energy into electrical energy.将电能转化成机械能以及将机械能转化为电能
C、eliminates the signal-to-noise energy. 消除信号-噪声能量
D、produces high-speed electrons in metals.在金属中产生高速电子