单项选择题
A.copy to boy for 性别="男"B.copy file da.dbf to boy.dbfC.copy stru to boy fields 姓名,年龄,奖学金D.select *from da where 性别="男"into dbf boy
A.Y-△降压B.定子回路串电阻C.转子回路串电阻D.自耦变压器