关于对PSA产品纯度超标处理方法正确的有()。
A、适当减小操作系数或缩短吸附时间
B、适当调整各阶段的压力
C、提高进料
D、停工后更换吸附剂
参考答案:A, B, D
He came to a point ______ there was no more road to follow, and before him he could see nothing but a thick forest.
A.that
B.what
C.which
D.where
ZK-2型通讯控制器中ZKT-2型控制台的通讯电源额定电流为700mA。()