cut in表示插隊(duì)，超車。

　　如：He cut in at the head of the line.

　　他在隊(duì)伍的前面插隊(duì)。

　　The car overtook me and then cut in on me.

　　那輛小車超了我的車，然后插在我前面。

　　cut down 砍倒，降低，如cut down the trees砍樹、cut down the cost 降低成本、cut down on 減少,削減。