He devoted all his efforts _______ children.
A:educating
B:educate
C:education
D:to educating
Put the book ____ (in/on) the bag.
一个圆形杯垫的半径是4厘米,这个杯垫的周长是____厘米,面积是____平方厘米.
There are some ____ (woman) over there.