为进行有效的成本控制，许多企业引用了（）的概念，由主管人员对产品或服务的成本负责。
A.成本中心
B.管理系统
C.成本体系
D.预算控制
参考答案：A
改错(共5小题，每小题2分，共10分)
小题1:That is amazing that such an old man can climb a 1000-meter-high mountain.
小题2:On the another hand, the Chinese paintings will take a longer time to learn than oil paintings.
小题3:If I am you, I would work in a small mountain village.
小题4:Once you get into trouble, don’t be nervous; that is, take easy.
小题5: After being ill for 10 days, Mary is finally back on her foot again.
妊娠期龈炎患者的龈下菌斑中的优势菌为（）
A.变形链球菌
B.伴放线杆菌
C.牙龈卟啉单胞菌
D.中间普氏菌
E.金黄色葡萄球菌
