A:will
B:may
C:have to
D:should
I have ____ books and a ____ .
Give her a ______. She is doing her homework.
在平面直角坐标系中,O为原点,直线y=﹣2x﹣1与y轴交于点A,与直线y=﹣x交于点B,点B关于原点的对称点为点C.