it is high time有两种用法：一种是接主语+should+动词原形;一种是主语+动词过去式;两种结构可以互换的,是虚拟语气中的知识。还有一种结构就是it is high time+to do sth,不是虚拟语气……
例子：
1、It's high time that you started working.
你早该开始工作了。
2、It's high time to try it.
这是该试一试的时候了。
3、It's high time you left home for work.
你真该离家去上班了。
4、It's high time that we should take action to protect the water resources.
是我们采取措施保护水资源的时候了。
扩展资料
1、It's high time we took urgent and effective measures to curb this phenomenon. ① Firstly.
该到了我们采取紧急并有效措施来抑制这一现象的时候了。
2、It's high time that we protected the historical old buildings.
到了我们保护历史古建筑物的时候了。
3、I think it's high time you bought the house.
我看你现在是必须买这所房子的时候了。
4、It's high time mankind learned who I really am.
这是人类真正认识我的时候了。
5、I love the old barter system, it's high time to bring it back.
我喜欢旧的易货制度，现在是非常适合的时候把他们带回来
