已知展开式中,各项系数的和为64,则n等于()。
A.7
B.6
C.5
D.4
参考答案:B
解析:
因为二项式各项系数和所以2n=64,得出n等于6。
We _____ spend too much time in watching TV. [ ]
A. told don't
B. told not to
C. were told not to
D. were told to not
A/P和人工操纵都是通过对什么的控制来使舵面移动()。
A.PCU
B.A/P作动器
C.作动器
D.伺服器