There are quite a few good books here, some of _____ I can recommend to my students. [ ]

A. those

B. that

C. which

D. them

下列各项中，属于质量管理八项原则的有（）。

A.以顾客为关注焦点

B.员工作用

C.全员参与

D.过程方法

E.与需方互利的关系