若2x+1=3,则6x+3的值为____
鲸终生生活在海洋中,颈部不明显,具鳍,体表光滑无毛。但它是哺乳动物,而不是鱼类的主要原因是
在平面直角坐标系中,抛物线y=(x-1)2+1的顶点坐标是( )
— Why are you going to the gift shop?
— Because l want to buy a present for my mother today.