Smoking, ____ some smokers, might ease their anxiety sometimes, but ____ the addiction caused by their constant practice, it is really hard to give up.

A．according to; due to

B．according to ;because

C．as to; since

D．thanks to;if

M1432A型万能外圆磨床工作台自动往复运动由HYY21/3P-25T型（）控制。

A.溢流阀

B.调速阀

C.液压阀

D液压操纵箱