Many charities raise money _______ children in poor areas.
A:help
B:to help
C:helping
D:helped
点A为数轴上表示-2的动点,当点A沿数轴移动4个单位长度到点B时,点B所表示的数为( )
下列计算正确的是( )
x的2.5倍是27.5.(省略乘号)
解:____
x=____