$21-$ Using the joint notation system for defining manipulator configurations, sketch diagrams of the following robots

A$.($a$)$ TRT:R$,($b$)$ OLO, $($c$)$ TRT

B$.($a$)RR$:$T,($b$)$ VVR$,($c$)$ VROT

C$.($a$)$ RR:T$,($b$)$ TVR:TR$,($c$)$ VROT

D$.($a$)$ TRL$,($b$)$ TVR:TR$,($c$)$ LVL