be动词后面可以加什么样的动词（形式）?

be动词后面的动词形式有三种可能：-ing:现在进行时,I'm trying to give you the right answer.-ed:被动语态,I'm told that you don't know her.to do:1.表示按计划或安排要做的事.例如：They said goodbye,little kn...