She did what she could _______ us. Though 3,000 dollars is a lot of money for her.
A:help
B:helped
C:helping
D:to help
下列图形中,既是轴对称图形又是中心对称图形的是( )
小明用如图所示的实验装置,探究反射光线与入射光线是否在同一平面内,应进行的操作是( )
如图漫画反映的是某中学把猫眼反装的做法,这种做法( )