电容式接近开关对（）的灵敏度最高。
A.玻璃
B.塑料
C.纸
D.鸡饲料
参考答案：D
Not until he got to the factory _______that he had lost his papers.
A．he found
B．did he find
C．had he found
D．has he found
法律对社会关系的调整，是通过强制和惩罚来实现的。 ( )
