A:①④
B:②④
C:③④
D:②③
如图所示,是“探究杠杆平衡条件”的装置图.
It is ____(belief) that the place will become a paradise if people live in peace.
如图,过原点O的直线AB与反比例函数y=kx(k>0)的图象交于A、B两点,点B坐标为(﹣2,m),过点A作AC⊥y轴于点C,OA的垂直平分线DE交OC于点D,交AB于点E.若△ACD的周长为5,则k的值为____.