begin的现在分词和过去式是什么

　　begin例句

　　The project is beginning to show results.

　　这项工程开始显出成效。

　　I was beginning to think you'd never come.

　　我开始以为你是不会来了。

　　The pressure of work is beginning to get to him.

　　工作的压力使他烦恼起来。

　　We began work on the project in May.

　　我们于五月份启动了这项工程。