That's a long shot.

那是一个长期的任务。

youdao

I hope to double my profits, but I know that's a long shot.

我希望能让自己的收益翻倍，但是也知道没多大戏。

youdao

She and her husband are trying to help him do that, but it's a long shot - a very expensive one.

NPR: Iran Facing Dangerous Brain Drain

It's a long shot, given that primaries tend to be dominated by highly ideological voters.

CNN: Will Bob McDonnell be a presidential contender?

But it was not until the dying seconds of a tepid first half that either goal came under serious threat, with James fumbling Ashton's swerving long-range shot behind for a corner.

BBC: West Ham 0-1 Portsmouth