^_ Time to go to bed, Mary.  

^_ Oh, Mum, I won't go to bed        I have finished my homework.  [ ]

A. after

B. since

C. until

D. as soon as

在一般情况下，材质编辑器工具栏中的Put Material to Scene按钮和Make Material Copu按钮只有（）可以使用。