UN Secretary-General联合国秘书长
uN Jin-huo林金火
un rince-doigt在线英语学习湿纸巾
Un après-midi整整一下午
UN head-quarters联合国总部
UN NGO-CSW联合国妇女地位委员会
Un intermittent - basse指拨电贝司
un e-readiness电子就绪
un water-africa联合国非洲之水
PREFIX（前缀） Un- is added to the beginning of adjectives, adverbs, and nouns, in order to form words that have the opposite meaning. (用于形容词，副词和名词前)表示“非，否”
My father was an unemployed labourer.
我父亲是一个没工作的劳工。
PREFIX（前缀） Un- is added to the beginning of a verb that describes a process, in order to form another verb that describes the reverse of that process. (用于动词前)表示“做相反的动作”
He undressed and draped his clothes neatly over the back of the chair.
他脱下衣服，然后小心地搭在椅背上。
PREFIX（前缀） Un- is added to the beginning of the past participle of a verb, in order to form an adjective that means that the process described by the verb has not happened. (用于动词过去分词前)表示“该动词描述的动作并未发生”
The theory remains untested.
该理论仍未经过验证。