Forbes magazine has named President Hu Jintao as the world's most powerful person, a move that

analysts say shows global ________ of China's contribution to the world's economic recovery. [ ]

A.acknowledgement

B.commitment

C.complement

D.requirement

若以长6厘米、宽4厘米的长方形的长为轴旋转，可得一个底面半径为______、高为______的圆柱；若以三条边长分别是3厘米、4厘米、5厘米的三角形的某条直角边为轴，旋转得一个较大的圆锥，它的底面半径是______、高是______．