已知曲线C的极坐标方程是ρ=4cosθ．以极点为平面直角坐标系的原点，极轴为x轴的正半轴，建立平面直角坐标系，直线l的参数方程是$\left\{\begin{array}{c}x=1+\frac{\sqrt{2}}{2}t\\ y=a+\frac{\sqrt{2}}{2}t\end{array}\right.$是参数）．

（Ⅰ）写出曲线C的普通方程；

（Ⅱ）若直线l与曲线C相交于A、B两点，且|AB|=$\sqrt{14}$，求a的值．

—Are you going to have a part time job during the summer vacation?

—Yes. I think I shouldn't always        my parents since I've grown up.