I'm making progress this term, so I am very proud ________ myself.
A:about
B:in
C:for
D:of
设集合U={1,3,5,7,9},A={1,|a+1|,9},∁UA={5,7},则实数a的值为____
若32×83=2n,则n=____。
某人不小心将一块正五边形玻璃打碎成四块,现要到玻璃店配一块完全一样的玻璃,那么最省事的方法是( )