two years ago是什么時態的標志詞

　　例句;

　　I used to smoke but I gave up two years ago.

　　我過去抽煙，但兩年前就戒了。

　　Martha graduated from high school two years ago.

　　瑪莎兩年前高中畢業。

　　The cost is about half as much again as it was two years ago.

　　現在的價格比兩年前提高約一半。

　　We were divorced two years ago and she has since remarried.

　　我們兩年前離了婚，之后她又再婚了。

　　Come on, Sue, that was two years ago.

　　得了吧，休，那是兩年前。