grow的過去式和過去分詞是什么？

　　例句：

　　The economy continues to grow.

　　經(jīng)濟持續(xù)增長。

　　They began to grow as individuals.

　　他們開始發(fā)展獨自的個性。

　　We are trying to grow the business.

　　我們正在努力擴展業(yè)務。