以下是“同時(shí)發(fā)生”和現(xiàn)在“正在發(fā)生”：John is standing at the gate.He is waiting for his friends.-------John is standing at the gate,waiting for his friends.(這里standing和waiting同時(shí)發(fā)生,并且正在發(fā)生...發(fā)生在過去也可以是正在發(fā)生，不是嗎你說的“正在”應(yīng)該指的是“現(xiàn)在”。如果拋開“現(xiàn)在”這個(gè)概念，同時(shí)發(fā)生就是“同時(shí)正在發(fā)生”，----------這應(yīng)該就是你的想法了。呵呵。