有用的

• useful
• helpful
• subservient
• serviceable
• available
• usable
• expedient
• salutary
• favourable
• profitable
• helpfully
• useable

例句

1. 这是有用的书，更难得的是不贵。
   It is a useful book and, what is more, not an expensive one.
2. 有点依靠的东西总是有用的。
   It's always useful to have something to fall back on.
3. 向他解释理由是没有用的。
   It is no use explaining the reason to him.
4. 这会非常有用的。
   It'll be most useful.
5. 她是个应该结交的有用的人。
   She is a useful person to know.
6. 跟他们讨论终止合同是没有用的。
   It's no use to discuss the termination of contract with them.
7. 约翰经常设法和对他有用的人结交。
   John always tries to cultivate people who are useful to him.