have a few, several, etc. irons in the fire idiom
同时有几件事要做；同时有数种可能
to be involved with many activities or jobs at the same time or to make certain that there are always several possibilities available
If that job application doesn't work out I've got a couple more irons in the fire. 如果那份求职申请没有结果，我还有另外几个选择。