Which three statements about RSTP are true？（）

A、RSTP significantly reduces topology reconverging time after a link failure.

B、RSTP expends the STP port roles by adding the alternate and backup roles.

C、RSTP port states are blocking，discarding，learing，or forwarding.

D、RSTP also uses the STP proprsal-agreement sequence.

E、RSTP use the same timer-baseed process as STP on point-to-point links.

F、RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.