Answer: They are often prepared to do jobs turned down by other people.
Explanation:
Verb particle constructions are also called phrasal verbs and are formed by a verb and a particle, which can be either an adverb or a preposition. They are used to express a figurative meaning, like "count on", and "clean up".
In this example, the idea of jobs "that aren't wanted" is rephrased using the phrasal verb "turn somebody/something down", which refers to refusing to accept an offer or the person who makes it.