油漆6根柱子，柱子截面是边长0.5米的正方形，柱子长4米，每平方米需要费用3.40元，买油漆需要多少元？
0.5×4×4×6×3.40=163.2（元）
在旋转对象移动时按下（）键，可以约束移动的方向：
A.Shift
B.Ctrl
C.Alt
D.Space
What he has learned through practice before _____ him a lot in his future work.
A．helping
B．helped
C．it helps
D．will help
