It is _____ to make another effort and try to finish the work ahead of the time _____ for it to be finished. [ ]

A. worth; fixed    

B. worthwhile; made  

C. worthy; fitted    

D. worthwhile; set

金属热处理的目的是（）。

A.使晶粒细化

B.使晶粒长大

C.使结构紊乱

D.使结构还原

E.增加内应力