Put in by or with. the boy was hit a stick. their children were frightened thunder. her room is cleaned a vacuum-cleaner. the test will be done the best pupil. these rings were sold a newcomer.

The boy was hit with a stick.

Their children were frightened by thunder.

Her room is cleaned with a vacuum-cleaner.

The test will be done by the best pupil.

These rings were sold by a newcomer.

*Предлог with пишется, когда речь идет о том, каким инструментом/предметом кто-то другой совершил действие. А вот когда надо написать, кем совершено действие, мы используем предлог by.