And as soon as the TV program came out more than 30 years ag

And as soon as the TV program came out more than 30 years ago，Western children became interested in reading this story because the clever Monkey King keeps fighting to help the weak and never gives up.这段话中为什么“became和interested”同时用过去式，在这里表示表示什么时态？第一个回答的采纳！