问题
选择题
We often practice _______. [ ]
A. to play football
B. playing football
C. playing the football
D. to play the football
答案
答案：B
搜题请搜索小程序“爱下问搜题”
We often practice _______. [ ]
A. to play football
B. playing football
C. playing the football
D. to play the football
答案：B
菲合尔在澳大利亚的伯斯冒险世界进行了超高特技跳水表演，他从30m高
的塔上跳下，准确地落入水池中, 若已知水对他的阻力(包括浮力)是他重力的3.5倍，他在空中时, 空气阻力是他重力的0.2倍，则水池的深度至少为_______m．