kinds是什么意思啊

　　These kinds of questions often appear in the exam.

　　這幾類問題在考試中經常出現。

　　Human beings are genetically programmed to learn certain kinds of language.

　　人類生來有學習某幾種語言的遺傳因素。

　　I like all kinds of music from opera to reggae.

　　我喜歡各種音樂，從歌劇到雷蓋都喜歡。

　　In crude terms, the causes of mental illness seem to be of three main kinds.

　　簡略地說，導致精神病的原因看起來主要有三種。