complex adj. 復雜的，合成的，綜合的 n. 聯合體
例句：It's a complex question and your answer was too simple.
這是一個復雜的問題，你的回答來得太簡單了。

complicated adj. 復雜的，難解的
例句：The tax laws are so complicated that only an expert can provide enlightenment.
稅務法非常復雜，只有專家才能解釋清楚。

complication n. 復雜化，（使復雜的）因素
例句：Lily's both parents work, which adds complications to their family life.
莉莉的父母都工作，這給他們的家庭生活增添了困難。

intricate adj. 復雜的，錯綜的，難以理解的
例句：The intricate machine requires a skilled operator.
這種復雜的機器須由技能熟練的人操作。

perplex v. 困惑
例句：When new math was introduced into schools, many parents were perplexed by it.
當學校開設新的數學課時，許多家長時此感到迷惑不解。