speak的过去式和过去分词是什么呢？

　　双语例句

　　1.He tried to speak, but for once, his voice had left him.

　　他想说话，却一时语塞。

　　2.When speaking to the seminar Mr Franklin spoke of his experience, gained on a recent visit to Trinidad.

　　在研讨会上发言的时候，富兰克林先生谈到了他最近游览特立尼达的经历。

　　3.He said it was the job of the Church to speak for the underprivileged.

　　他说，为贫困群体说话是教会的义务。