unless 与 as long as / provided that的分别

题目

unless 与 as long as / provided that的分别
(1)You can watch this film as long as / provided that you are not under 18.
这题可否变成:you can watch this film unldess you are not under 18.
unless 和 as long as / provided that 在一些意思看上去都可以使用的句子,有什麼可以分辨的吗?

答案