适应 is a VERB like adapt...it often means the animals adapt the environment or something else. 适合 is a VERB like suit,match... it often use to express if the size,colour,etc suit you 合适 is an ADJ like appropriate,suitable,fit... 它能适应多种恶劣的生存环境. 这种款式不适合我. 你这样做不合适. 穿牛仔裤出席舞会(是)不合适(的). hope it can help

For 适应 ：If I got a new job,I need spend more time to suit new status. For适合：If a company hiring new stuff ,they would like find out the fittest person from candidate for the position . 适合 and 合适 doesn't have a lot difference ,they are in same meaning .I think "合适“is adj. "适合”is verb. 你可以使用 这件sweater 很适合我穿。等同于我穿这件sweater 和合适。 “合适”后面不能加其他role.