英语翻译
1-they experiment was a success.
2-they experiment had succeeded.
3-they experiment succeeded.
不好意思代词打错了。
1-their experiment was a success....
2-their experiment had succeeded....
3-their experiment succeeded....
补充下，我认为：
第一、三句都用了一般过去时，到底哪个是对的？
第二句是完成时。表述是否正确？