junior表达的是初中，英语表达初中：junior high school、junior middle school；表达高中：senior high school、senior middle school。
junior的用法
用作形容词 (adj.)
I started the job as a junior secretary.
刚开始这份工作时，我是初级秘书。
The president was so young that he was junior to some of his employees.
总裁的年龄甚至是比他的一些雇员还小。
He likes to lord it over the junior staff.
他喜欢对下级职员逞威风。
用作名词 (n.)
She ranks as my junior in the clan.
她的辈分比我小。
You see, I am a sophomore and Miss Yang is a junior.
你瞧，我是2年级的，杨小姐是三年级的。
junior的例句
1、She now lives with actor Denis Lawson, 10 years her junior.
她现在与比她小10岁的演员丹尼斯·劳森同居。
2、The vacant W.B.C. junior-lightweight title has been called off.
空缺的世界拳击理事会次轻量级头衔被取消了。
3、Our doctor diagnosed a throat infection and prescribed antibiotic and junior aspirin.
我们的医生诊断是喉部感染，并且开了一些抗生素和小剂量阿司匹林。
