It is said that pandas ______ in our country year by year.
A:are being disappeared
B:are disappearing
C:will be disappeared
D:will disappear
在平面直角坐标系中,抛物线y=﹣x2﹣2x+3与x轴交于A,B两点(A在B的左侧),与y轴交于点C,顶点为D.