已知二次函数y=(x﹣3)2图象上的两点A(3,a)和B(x,b),则a和b的大小关系是a____b.
— The cars made in Germany are more expensive than ________ made in Japan.
— Yes, I can't agree more. But they're much better.
北宋时期毕昇的重要贡献是( )