8.5 cease doing/to do
	cease to do　 长时间，甚至永远停做某事。 cease doing　 短时停止做某事，以后还会接着做。 　　That department has ceased to exist forever. 　　那个部门已不复存在。 　　The girls ceased chatting for a moment when their teacher passed by. 　　姑娘们在老师走过时，停了会聊天。