来自宝岛台湾的客人给孙老师带来了家乡特产,这份特产最有可能是( )
圆x2+y2﹣2x=0和x2+y2+4y=0的位置关系是( )
— Nowadays more and more foreigners are becoming interested in Beijing Opera.
—That's true. It's an important part of Chinese____________.
下列四幅热力环流示意图中,与图中所示气压分布状态相符的是( )