There are things each of us can do every day. [ ]
A. so many
B. so much
C. too much
答案:A
隋朝在中国历史上的最大贡献是[ ]
A.重新统一了南北
B.建立了三省六部制
C.创立了科举制
D.开通了大运河
简述业务通道产生误码的原因及处理方法?