is后面加什么 lt

1、lt is about time.-And it's a significant raise too!是时间该告诉我们了.-这可是一个重要的升迁！

2、lt is the decision of this committee.这是委员会的决定.

3、lt is an historic day.今天意义非凡

4、It is important for us to study English.学习英语对我们来说特别重要。