They worked quickly to catch up. Less than a year later, on October first,nineteen fifty-eight, the National Aeronautic and Space Administration,or NASA, began operations.

VOA: special.2010.08.20

I'm really tired and I have a lot of school work to catch up on.

我真是累坏了，我还有许多落下的功课得补起来。

I'd like 实战 - SpeakingMax英语口语达人