_______ the gained knowledge, he made his new inventions one after another.[ ]

A. Owing to

B. According to  

C.  Due to     

D. By

选用超声耦合剂错误的是

A．耦合剂越厚越好
B．应满足阻抗匹配条件
C．排除空气，增加透声性
D．让超声尽量多进入人体
E．特性阻抗接近人体(软组织)的特性阻抗