已知函数f（x）=x²+4x+3，

（1）若g（x）=f（x）-cx为偶函数，求c．

（2）用定义证明：函数f（x）在区间[-2，+∞）上是增函数；并写出该函数的值域．

Some so-called climate travelers _______ in one place for a few months and then move on to some other places as the weather changes.

A．have stayed

B．are staying

C．stay

D．stayed