下列号码中哪个表示中国发明专利申请号()
A.200300472.6
B.ZL2004100001
C.200420000123.5
D.200510081201.7
参考答案:D
Shopping online can save much time as you _____ go to a shop or walk around crowded shopping centers.[ ]
A. don't have to
B. oughtn't to
C. won't
D. mustn't
某医院用两种方案治疗急性肝炎,观察疗效为:无效、好转、显效和痊愈。比较两种方案疗效之间的差别,应采用的统计分析方法是()
A.χ检验
B.t检验
C.方差分析
D.秩和检验
E.相关回归分析