take on the role of：承担起……的作用，扮演…的角色，例句分析：
1.This directory server is shutting down,and cannot take ownership of new floating single-master operation roles.这个目录服务器已关闭,并且不能接受新的浮动单主机操作角色的所有权；
2.He always take the role of a mediator in any dispute他总是在争论中充当调停人的角色；
3.We should take better advantage of the role of monetary policy.要进一步发挥货币政策的作用。
take off：起飞，脱掉。
例句：
1.We eventually took off at 11 o''clock and arrived in Venice at
1.30. 我们终于在11点起飞，1:30到达威尼斯。
2.They need to expand the number of farmers who are involved if the scheme''s going to really take off .这个方案要想真正成功，他们就需要增加参与的农场主的人数。
3.He took off at once and headed back to the motel .他立刻离开，回到汽车旅馆。
4.He wouldn''t take his hat off .他不肯摘下帽子。
5.Mitchel''s schedule had not permitted him to take time off .米切尔的日程安排使他无法休假。
Take your places, please, we are about to start.各位请入席，我们就要开始了。
In case of my absence, who will take my place?要是我万一不能来，谁来顶替我?In case of my absence, some one will take my place.如果我不到,将有别人代替。
If there is no room for you there, take my place here.如果那边没有空位,坐我的位置吧。
He took my place during my absence.在我缺勤期间他代替了我。