下列关系式正确的为(wl为塑限、wp为液限,ws为缩限)()

A:wp>wl>ws B:ws>wl>wp C:wl>ws>wp D:wl>wp>ws

当前目录为根目录,要删除C:盘根目录下WS子目录中后缀为.TXT的所有文件,可使用()。

A:DELC:*.TXT B:DELWS\*.TXT C:DEL\WS\*.TXT D:DELC:\WS\*.TXT

WS指的是()

A:等效噪声量子数 B:量子捡出率 C:调制传递函数 D:维纳频谱 E:特性曲线

设有学生表S(学号,姓名,性别,年龄),查询所有年龄小于等于18岁的女同学、并按年龄进行降序排序生成新的表WS,正确的SQL命令是______。

A:SELECT*FROM S WHERE性别=’女’AND年龄<=18 ORDER BY 4 DESC INTO TABLE WS B:SELECT*FROM S WHERE性别=’女’AND年龄<=18 ORDER BY年龄INTO TABLE WS C:SELECT*FROM S WHERE性别=’女’AND年龄<=18 ORDER BY’年龄’DESC INTO TABLE WS D:SELECT*FROM S WHERE性别=’女’OR年龄<=18 ORDER BY’年龄’ASC INTO TABLE WS

设有学生表S(学号,姓名,性别,年龄),查询所有年龄小于等于18岁的女同学,并按年龄进行降序排序生成新的表WS,正确的SQL命令是( )。

A:SELECT * FROM S B:WHERE 性别='女' AND 年龄<=18 ORDER BY 4 DESC INTO TABLE WS C:SELECT * FROM S D:WHER E性别='女' AND 年龄<=18 ORDER BY 年龄 INTO TABLE WS E:SELECT * FROM S F:WHERE 性别='女' AND 年龄<=18 ORDER BY '年龄' DESC INTO TABLE WS G:SELECT * FROM S H:WHERE 性别='女' OR 年龄<=18 ORDER BY '年龄' ASC INTO TABLE WS

设有学生表S(学号,姓名,性别,年龄),查询所有年龄小于等于18岁的女同学、并按年龄进行降序排序生成新的表WS,正确的SQL命令是【 】。

A:SELECT*FROM s WHERE 性别=′女′AND年龄<=18 ORDER BY 4 DESC INTO TABLE WS B:SELECT * FROM S WHERE性别=′女′AND年龄<=18 ORDER BY年龄 INTO TABLE WS C:SELECT * FROM S WHERE性别=′女′AND年龄<=18 ORDER BY ′年龄′ DESC INTO TABLE WS D:SELECT * FROM S WHERE性别=′女′OR年龄<=1 8 ORDER BY′年龄′ ASC INTO TARLE WS

设有学生表S(学号,姓名,性别,年龄),查询所有年龄小于等于18岁的女同学、并按年龄进行降序排序生成新的表WS,正确的SQL命令是【 】。

A:SELECT*FROM s WHERE 性别=′女′AND年龄<=18 ORDER BY 4 DESC INTO TABLE WS B:SELECT * FROM S WHERE性别=′女′AND年龄<=18 ORDER BY年龄 INTO TABLE WS C:SELECT * FROM S WHERE性别=′女′AND年龄<=18 ORDER BY ′年龄′ DESC INTO TABLE WS D:SELECT * FROM S WHERE性别=′女′OR年龄<=1 8 ORDER BY′年龄′ ASC INTO TARLE WS

设有学生表S(学号,姓名,性别,年龄),查询所有年龄小于等于18岁的女同学、并按年龄进行降序排序生成新的表WS,正确的SQL命令是( )。

A:SELECT* FROM S WHERE 性别='女' AND 年龄<=18 ORDER BY 4 DESC INTO TABLE WS B:SELECT* FROM S WHERE 性别='女' AND 年龄<=18 ORDER BY 年龄 INTO TABLE WS C:SELECT* FROM S WHERE 性别='女' AND 年龄<=18 ORDER BY '年龄' DESC INTO TABLE WS D:SELECT* FROM S WHERE 性别='女' OR 年龄<=18 ORDER BY '年龄' ASC INTO TABLE WS

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