Write a regular expression for the following languages.

$($a$)$ All strings of a$$s$,$ b$$s$,$ and c$$s that start with cbc$.$

$($b$)$ All binary strings that contain exactly two $1$s$.$

$($c$)$ All strings of a$$s$,$ b$$s$,$ and c$$s that do not contain more than $1$ a$,2$ b$$s$,1$ c$.$

$($d$)$ All strings of a$$s$,$ b$$s$,$ and c$$s with an even number of a$$s$.$

$($e$)$ Binary string with no two consecutive $1$s$.$

$($f$)$ All strings of $1$s and $0$s where the numbers alternate, for instance,$101010,$ and $0101.$