下列各方程中,是二元一次方程的是 ( )
A:x3-2y=y+5x
B:3x+2y=2x+2y
C:15x=y2+1
D:y4=3x-5y6
——The little girl often has nothing for breakfast, ________she?——_______. Because she often gets up late and is afraid of being late for school.