重点讲解：
1. a type of
一种，一类（人或事物）；
eg. Cactus is a type of green desert plant.
仙人掌是一种绿色的沙漠植物。
eg. I am a very determined type of person.
我是那种非常坚决的人。
2. be known as
称为；叫做；
eg. The disease is more commonly known as Mad Cow Disease.
这种疾病更通俗的名称是疯牛病。
eg. Our school had a mascot known as Freddy Bird.
我们学校有一个名叫“弗雷迪小鸟”的吉祥物。
3. be classed as
把…归类；把…视为；
eg. Immigrant workers were classed as resident aliens.
移民来的工人已归入外侨类。
eg. t is classed as an agricultural state.
这个州被划为农业州。