根据句意，在相应的横线上，写出括号内所给单词的适当形式。
①It is getting more and more ____  (pollute). We should do something to solve the problem.
②I don't like the persons whose clothes are____  (tidy).
③They designed a car____ (special) for disabled people.
④Here is a list of the early ____  (settle) names. They have lived there for 30 years.