2010020011

How many of the following functions have exactly two asymptotes? $$$$ $f(x)={\left(\frac{4+x}{4-x}\right)}^4,$ $g(x)=\frac{x^3}{(x-2{)}^2},$ $h(x)=\sqrt{6-4x},$ $i(x)=\frac{x^2}{4-x^2}$