proposition about the Fibonacci numbers and a proof $($by induction$)$ is presented below. Complete all of themissing spaces with appropriate terms or phrases. Note that for this problem we are defining the Fibonacci sequence startingat n $=1,$ i$.$e$.$F$1=$ F$2=1$ and Fn $=$ Fn$1+$ Fn$2.$Proposition. For every natural number n $1,$ if $3|$n then Fn is even.