I bought a dress for only 10 dollars; it was a real _____.
A:exchange
B:bargain
C:trade
D:business
如图两个椭圆分别表示正数集合和整数集合
函数y=loga2x-3+22的图象恒过定点P,P在幂函数f(x)的图象上,则f(x)=____