useful
/ˈjuːsfʊl/adjective
1- able to be used for a practical purpose or in several ways有用的, 实用的, 有效的：
aspirin are useful for headaches.
阿司匹林治头疼有效。
1.1
- informal very able or competent in a particular area〈非正式〉（特定领域）有能力的; 胜任的：
a useful pace bowler.
胜任的快投手。
短语
make oneself useful
- do something that is of some value or benefit to someone做对人有利的事：
make yourself useful - get Jenny a drink.
做点好事——帮珍妮拿杯饮料。
派生词