jumper是什麼意思解釋一下

　　He's a high-jumper.

　　他是一位跳高的.運動員。

　　The jumper from the Round Tower worked for him.

　　圓塔上的跳塔者，為他工作。

　　His clothes were dark and he wore a woolly jumper.

　　他的外套是暗色的的，穿了一件羊毛套衫。

　　Who has a lucky red jumper or something like that?

　　誰有一個幸運兔或者之類的東西？

　　The jumper-wearing Mr Marchionne is not given to self-doubt.

　　身穿套頭衫的馬爾基翁內不喜歡自我懷疑。