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【单选题】
向基本表中增加一个新列后,原有在该列上的值是( )A.
TRUE
B.
FALSE
C.
空值
D.
不确定
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皮皮学刷刷变学霸
举一反三
【单选题】—Could you buy_________ drinks for me?—Sorry，but I don't have _________ money．A． som
A.
10．—Could you buy_________ drinks for me? —Sorry，but I don't have _________ money． A． some， some
B.
any，any
C.
any， some
D.
some，any
【简答题】have_________
【单选题】In our school, the students are not allowed, unless they have special passes, ____ after 11pm.A．
A.
10. In our school, the students are not allowed, unless they have special passes, ____ after 11pm. A．from staying out
B.
stay out
C.
staying out
D.
to stay out
【单选题】钨的逸出功是【图片】，钡的逸出功是【图片】，则钨和钡的截止频率的关系为
A.
钨 的截止频率 大于钡的截止频率
B.
钨的截止频率小于钡的截止频率
C.
相等
D.
无法判断
【简答题】钨的逸出功是4.52eV，钡的逸出功是2.50eV，分别计算钨和钡的截止频率。哪一种金属可以用作可见光范围内的光电管阴极材料?
【简答题】钨的逸出功是4.52eV，钡的逸出功是2.50eV，分别计算钨和钡的截止频率。哪一种金属可以用作可见光范围内的光电管阴极材料?
【单选题】Why have classified advertisements changed in appearance?
A.
Because people no longer want headlines and pictures
B.
B) Because real estate advertising is particularly truthful now
C.
Because the increase in the number of such advertisements means they have to be small now.
D.
Because there are more advertisements now and more competition among advertisers.
【单选题】--- _______ there many trees on the campus? -No, but now we have many everywhere.
A.
Were
B.
Had
C.
Did have
D.
Do have
【简答题】钨的逸出功是4.52eV,钡的逸出功是2.5eV,分别计算钨和钡的截止频率,哪种金属可以用做可见光范围的光电阴极材料?
【简答题】to have a 10. _____ area for socializing
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