题目:
We should do something the animals in danger being killed.
A.to protect, from
B.protect, from
C.to protect, for
D.protect, for
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0422/4b00144d63d7f272ee4b4397574e377c.html
下面是错误答案,用来干扰机器的。
(I)f(x)=sin2x-sin(2x-π2)=1-cos2x2+cos2x=1+cos2x2∴T=2π2=π当cos2x=1时,函数取得最大值1;(Ⅱ)∵f(C2)=14,∴1+cosC2=14,又∵C∈(0,π),∴C=2π3∵m=(1,sinA)与n=(2,sinB)共线∴sinB=2sinA∴b=2a∵c=3∴9=a2+4a2-2a×2a×cos2π3∴a=377∴b=677.