-- Tom made mistakes in the exam in our class.
-- So he did. Because he did it .
A:less; carelessly
B:most; careless
C:the most; most carelessly
用火柴棒摆“金鱼”,如图所示:按照上面的规律,第n个“金鱼”图需要火柴棒的根数为( )
(不考虑Mg2+和Al3+的水解及水的电离所引起的离子总数的变化)
如图已知AB∥CD, ∠2=2∠1,则∠3=( )