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【简答题】
设计一个成绩管理系统,此数据库中对每个学生保存其相应信息:包括:学号,姓名,性别,年龄,班级。对每门课存有:课程号、课程名、学分、开课院系。对每门选修的课程存有学号、课程号、成绩。要求:给出E-R图,再将其转换为关系模型并给出各关系的主关键字。(画图拍照上传)
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举一反三
【单选题】He asked me ▲ the film.
A.
had I seen
B.
have I seen
C.
if I have seen
D.
whether I had seen
【单选题】The film 'Aftershock' touched me deeply. Much of _____ happened in the film was true. [ ]
A.
which
B.
that
C.
what
D.
it
【单选题】下列关于气雾剂的特点错误的是()
A.
可以用定量阀门准确控制剂量
B.
具有速效和定位作用
C.
由于容器不透光、不透水，所以能增加药物的稳定性
D.
由于起效快，适合心脏病患者使用
E.
药物可避免胃肠道的破坏和肝脏首过作用
【单选题】“Have you seen the film?” he asked me. → He asked me _______ the film.
A.
had I seen
B.
have I seen
C.
if I have seen
D.
whether I had seen
【简答题】The film brought me to the times＿＿＿I was taken good care of in that small village．
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