根据句意，用括号内所给单词的适当形式填空
Teenagers shouldn’t keep worries to _____________ (they). They can tell them to their parents.
—Are these the ______________ (swim) watches?  —Yes, they are.
____________ (luck), Tom bought the last storybook in that bookshop yesterday evening.
The shy boy tried his best, but did ______________ (bad) among all the members in the club.