of no use

例句：

1. 1. I've tried everything but it still won't work.
   我已经试过了，但仍然不管用。
2. 2. Thenew software is of no useto us.
   这个新的软件对我们来说毫无用处。
3. 3. His advice was of no use tome.
   他的建议对我来说毫无帮助。