用滑轮组拉出陷入泥中的汽车.在图中画出最省力的绳子绕法.
只有一个动滑轮,要求最省力,绳子先系在动滑轮的固定挂钩上,然后绕过左边的定滑轮,再绕过动滑轮.
故答案为:
The hunter said he was lucky to get out of the forest____.
A.living
B.alive
C.lively
D.live
a,b,c三个数的平均数是6,则2a+3,2b-2,2c+5的平均数是( )
A.6
B.8
C.12
D.14