Qualitatively plot the function $f(t)$ in the time domain for the given $F(s)$ in the Laplace domain using the poles of $F(s).$ Do not use the inverse Laplace transform.

a$)F(s)=\frac{1}{s+3}$

b$)F(s)=\frac{e^{-2s}}{s+3}$

c$)F(s)=\frac{1}{s^2+1}+\frac{1}{s-3}$

d$)F(s)=\frac{1}{s^2-4s+8}$