将函数f（x）=log₂（x+1）的图象向左平移1个单位，再将图象上的所有点的纵坐标伸长到原来的2倍（横坐标不变），得到函数y=g（x）的图象．

（1）求函数y=g（x）的解析式和定义域；

（2）求函数y=F（x）=f（x-1）-g（x）的最大值．

Those who failed to get into the art exhibition ________ disappointed as many of the artists who should have appeared did not come.

A．didn’t need feel

B．needn’t have felt

C．mustn’t have felt

D．couldn’t have felt