The front wheel of the first bike is almost __________ of the back one.
A. five times size
B. five times the sizes
C. five times the size
D. five time size
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We produced __________ cars this month as we did last month.
A. twice as many
B. as twice many
C. as many twice
D. twice many as
抛掷一颗骰子一次,记事件A表示:出现偶数点,事件B表示:出现3或6点,则事件A与事件B是相互独立事件
A. 对
B. 错
某元素基态原子,有量子数 n=4、l=0、m=0 的二个电子,有 n=3、l=2 的 10 个电子,该元素位于周期表的位置是( )。
A. 四周期,ⅡB族
B. 三周期,ⅡA族
C. 三周期,ⅡB族
D. 四周期,ⅡA族
在氢原子中3s和3d哪一个状态的能量高?( )
A. 3s
B. 3d
C. 相同