python语言中以下不符合规则的标识符是____

A. 以产品为中心

B. 以客户为中心

C. 以数据为中心

D. 以业务为中心

A. for中还有for

B. while中还有 while

C. for中有while

D. while中有for

A. 随机填充

B. 统计法填充

C. 模型填充

D. 专家经验补全

A. 市场风险

B. 操作风险

C. 国别风险

D. 信用风险

A. select * from table_1 where username like ‘%yue%’

B. select * from table_1 where username like ‘yue%’

C. select * from table_1 where username like ‘wang%’

D. select * from table_1 where username like ‘li%’

A. SELECT cust_name FROM Customers1 UNION SELECT cust_name FROM Customers2

B. SELECT cust_contact FROM Customers1 UNION SELECT cust_name, cust_contact FROM Customers2

C. SELECT * FROM Customers1 UNION SELECT * FROM Customers2

D. SELECT cust_name FROM Customers1 UNION SELECT * FROM Customers2

A. select id from t where substring(name, 1,3)=＇abc＇

B. select id from t where name like ＇abc%＇

C. select id from t where num/2=100

D. select id from t where num=100*2

A. 协方差

B. 相关系数

C. 均值

D. 标准差