alien
单词辨析：
指属于另一个国家的，比 foreign 更正式，但没有 foreign 使用普遍，且常含贬义。
They were opposed to the presence of alien forces in the region.
他们反对外国军队驻扎在该地区。
He was interested in alien cultures.
他曾对异域文化感兴趣。
尤指来自热带国家的。
I like brightly-coloured exotic flowers.
我喜欢色彩鲜艳的异国花卉。
She prefers to travel to exotic places.
她更愿去有异国风情的地方旅行。
普通用词，泛指来自他国的或与他国有关的。
After living in foreign countries for many years, he returned home.
在国外居住多年之后，他回到了家。
All foreign troops must be withdrawn immediately and unconditionally.
所有外国军队必须立即无条件地撤出。
指来自、存在于或发生在海外国家的，只作定语。
There are many overseas students now coming to China to study Chinese.
现在有很多外国留学生来中国学习汉语。
The company has invested more money into its overseas market.
该公司已经将更多的资金投入了海外市场。
相关例句：
So you can kick some alien buttocks!
这样你就可以踢他们的屁股了！
An Englishman is an alien in america.
英国人在美国便是外国侨民。
Such an attitude is alien to most businessmen.
大多数商界人士都会对这样的态度感到陌生。
He was interned as an enemy alien at the outbreak of the Second World War.
第二次世界大战爆发时他被作为敌国侨民扣押了。
Both women had hired illegal aliens for child care
两个女人都曾雇过非法入境者照看孩子。
This paper discusses and identifies the concepts of alien species and alien invasive species;
讨论并界定了外来种和外来入侵种的概念；