secondary alkyl sulphate

例句：

1. 1. The secondary school students are preparingfor the entrance exam.
   中学生正在准备入学考试。
2. 2. The secondary school has a large librarythat houses many books.
   这所中学有一个很大的图书馆，藏书很多。
3. 3. Thesecondary school is located inthe city center, which isconvenient for commuting.
   这所中学位于市中心，通勤方便。