【单选题】对于贵金属催化剂来说,当采用沉淀法制备时,最主要的考虑的因素是 ( )。
【单选题】The man marked off his life not by the passing years but by _________.
A.
comparing himself with other people
B.
certain meaningful events
C.
counting the milestones of his life
D.
recalling events of the past
【单选题】下列显示对象中,不能用来做容器的是( )
【单选题】半机械半电子测量系统同时可以对( )个点进行测量
【单选题】下列显示对象中,不能用来做容器的是( )