B.
成绩表.综合成绩>=80 AND 成绩表.综合成绩 <=90< /div>
C.
成绩表.综合成绩>80 AND 成绩表.综合成绩<90< /div>
D.
80 <= 成绩表.综合成绩 <= 90< /div>
【单选题】听力原文:W: I haven't seen you here for a couple of weeks. Have you stop eating or something? M: No. Does it look as I've stopped eating? I've been spending a lot of time in the library. W: Working on a p...
A.
Writing papers for his classes.
B.
Meeting with his professors.
C.
Doing extra work in the chemistry lab.
D.
Working overtime as a librarian.
【单选题】下列关于偶然误差的叙述中,不正确的是( )
A.
偶然误差只要认真执行标准方法和测定条件是可以避免的
B.
当测定次数足够时,偶然误差中大小相近的正负误差出现的频率相等
【简答题】如图所示线性有源二端网络,已知R=10Ω时,I=1A;R=18Ω时,I=0.6A;若I=0.1A时,外接电阻R是( )Ω。【图片】
【简答题】我国通常采用的国际贸易作价方法为________。
【单选题】通常,我国在国家标准管理办法中规定:国家标准实施()内要进行复审。
【简答题】我国通常采用规定的安全电压各为:( )、( )、( )。