A.By computerized traffic control and personal computers at home.B.By computerized cas

外语类 专四 已帮助 人

A.By computerized traffic control and personal computers at home.

B.By computerized cash registers in the stores.

C.By computerized billing of credit card companies.

D.All of above items mentioned.

请帮忙给出正确答案和分析,谢谢!

热搜:a是b的充分条件,b是a的必要条件吗