Several is used to refer to a number of people or things that is not large but is greater than two.
some , a few
I had lived two doors away from this family for several years.
我和这家人相隔两户,做了几年的邻居了。
Several blue plastic boxes under the window were filled with CDs.
窗子下面的几个蓝色塑料盒子里装满了唱片。
Several hundred students gathered on campus.
几百名学生在校园集会。 。
Several means not many but more than two.
No one drug will suit or work for everyone and sometimes several may have to be tried.
没有一种药会对每个人都适用或有效,有时得试好几种。
If you talk about several of something, you mean not many but more than two of them.
The building was picketed by demonstrators, several of whom were well-known actors.
这座建筑被示威者们包围了起来,其中几位是著名演员。