—How do we go there?
— ____ ____.
直线l将圆x2+y2﹣2x+4y=0平分,且在两坐标轴上的截距相等,则直线l的方程是( )
— Has your brother completed this design?
— Not yet. He ____ (work) on it last night .
经X射线照射的紫花香豌豆品种,其后代中出现了几株开白花植株,下列叙述错误的是( )