Raft & River

A farmer wants to cross river and take with him a tiger,a sheep,and a carrot;
Rules:
1.The farmer is the only one who can steer the raft.He can only take one passenger the tiger,the sheep,or the carrot in addition to himself;
2.If the tiger and the sheep are alone on the same riverbank,the tiger will eat the sheep;
3.If the sheep and the carrot are alone on the same bank,the sheep will eat the carrot.
How can the farmer get the tiger,the sheep and the carrot across the river without any of them being eaten?
Point：
Different game levels have different game rules. Please read the game rules carefully！