某彩金是在黄金中加入铜、银等熔炼而成的合金,常用于制造首饰.从物质分类的角度看,彩金属于( )
A:混合物
B:纯净物
C:单质
D:化合物
函数y=3x是( )
下列反应中符合上述图象的是( )
Look, this is my city. There are many bikes and buses on the streets. Let's count. There are ____ bikes and ____ buses. Look here, there are also ____ taxis and ____ cars. My city is big and beautiful!