I had a good ____ ____.(暑假)
在横线上填上适当的数。
4 - ____ = 0 ____ - 0 = 5 0 + ____ = 3
2 + ____ =2 ____ + ____ = 0 ____ - ____ = 0
如图分类检索表中,鸽子的位置是( )