The man made another discovery, _____ of great importance to science. [ ]

A. which I think it is

B. I think which is

C. I think it is

D. which I think is

成本会计的环节是指成本会计工作应该做好的几个方面，具体包括（）。

A.成本的预测和决策

B.成本的核算和控制

C.成本的考核和分析

D.成本的计划

E.设置成本核算机构