电子商务的标准英文缩写是( )。
A.EB B.ECC.EDI D.DC
参考答案:B
Matt is now getting on very well with his new job and he earns _____ he did last year. [ ]
A. twice as much as
B. as twice much as
C. twice as many as
D. as twice many as
在社会经济的抽样调查中,简单随机抽样一般是指不重复抽样。