jump是什么意思解释一下

She hadn't heard his approach and jumped as the door opened.

她没有听见他走近的声音，所以门开时吓了一跳。

Do you want a ride? Jump in.

你想搭车吗？快上来吧。

The gentle touch of his hand on her shoulder made her jump.

他的手轻轻地触了一下她肩膀便使她跳了起来。

With his last jump he equalled the world record.

他的最后一跳平了世界纪录。

The negotiations took a jump forward yesterday.

谈判昨天取得进展。