引理

例句：

1. 1. The teacher invited us to join the party.
   老师邀请我们参加聚会。
2. 2. They led the group through the forest.
   他们带领小组穿过森林。
3. 3. The scientist introduced a new species to the world.
   科学家向世界介绍了一种新的物种。