介入: intervention

購入: purchase or buy

悟入: entering a stage of enlightenment (such as with Buddhism)

混入: the act of mixing; the state of being mixed; a mixing or mingling of two or more things, typically in an undesirable way

混入: to mix one thing into another, typically in an undesirable way; to mingle, to become mixed, to get mixed, typically in an undesirable way

歳入: : annual income or revenue

出入: income and expenses / 出入: free associations

代入: substitution

投入: investment / 豆乳: soy milk

導入: introduction (e.g. of new idea)