虚拟语气句型“it was (high)time that”

题目

虚拟语气句型“it was (high)time that”
请问,虚拟语气的句型“it was (high)time that”和“it is (high)time that”在句子表达的意思上有什么区别?请分别举例句说明,谢谢.

答案

it was (high)time that从句中使用had done
it was (high)time that we had set out
it is (high)time that从句中使用一般过去式
it is (high)time that we set out