亭在造园艺术中广泛应用,标志着园林建筑在空间上的突破。在建筑艺术上,亭集中了中国古代建筑最富名族形式的精华。()
参考答案:对
用文字表达式表示以下反应,并回答有关问题:
(1)二氧化碳通入澄清石灰水______.
观察到的现象是______.
(2)实验室用双氧水和二氧化锰混合制取氧气______,该反
应属于______反应类型.
(3)分解生成三种氧化物的反应______.
对于教学数据库的3个基本表:S(Sno,Sname,Ssex)、SC(Sno,Cno,Grade)、C(Cno,Cname,Teache),其中S表为学生表,SC为学生选课表,C为课程表,则对于语句:检索至少选修LIU老师所授课课程中一门课程的女生姓名,SQL语句错误的是()。
A.SELECT Sname FROM S,SC,C WHERE S.Sno=SC.Sno AND SC.Cno=C.Cno AND Teacher='LIU' AND Ssex='F'
B.SELECT Sname FROM S WHERE Ssex='F' AND Sno IN (SELECT Sno FROM SC WHERE Cno IN (SELECT Cno FROM C WHERE Teacher='LIU'))
C.SELECT Sname FROM S WHERE Ssex='F' AND EXISTS(SELECT * FROM SC WHERE SC.Sno=S.Sno AND EXISTS (SELECT * FROMC WHERE Teacher='LIU'))
D.SELECT Sname FROM S WHERE Ssex='F' AND EXISTS (SELECT * FROM SC WHERE SC.Sno=S.Sno AND EXISTS (SELECT * FROM C WHERE C.Cno=SC.Cno AND Teacher='LIU'))