Maps need regular updates.

Up to date现代的，时新的

To date迄今，到目前为止

Out of date=be dated

Date from=date back to=trace back to追溯到；自某时代存在至今（动词用现在时态作谓语，不用过去时）

5.convenit adj. convenience for convenience 为了方便

作表语时， 不可用人作主语，而是用事物作主语或用it作主语。

1)It is (was) convenient for sb. to do

你今天晚上出来方便吗？

2)Sth. be convenient to/ for sb.

-What time is convenient for you?

你什么时候方便啊？

3)作表语时后接主动不定式。

家具搬起来很方便。

6.highly (adv. ) highly developed countries 高度发达国家

speak highly of think highly / well/ much of

height (n) What is its height? What height is it?

7. Up to

1）多达（某个数量）

Up to 500 people can have dinner in the hall.

这个大厅可容纳500人就餐。

2）到。。。为止，直到

直到现在我一直认为海伦是个勤奋的孩子。

3）从事，忙于

What are you up to now?

你现在在做什么？

4）负责

It's up to me to help them with their maths.