jack...in（及物，必分）不再进行，放弃
He is going to jack the project in for lack of funds.由于缺乏资金，他准备停止这项工程。
He has jacked his job in and retired to the country.他已辞掉工作，退职下乡。
jack up（及物，可分）用千斤顶往上托
The automobile needs repairing.Please jack it up.这辆汽车需要修理，请把它顶起来。
To change a tyre，one must jack up one wheel of the car.为了换汽车的一个轮胎，必须用千斤顶把那个轮子顶起来。
join up（不及物）参军
He joined up at eighteen.他18岁参军。
Kerk joined up in the last months of the war.柯克在战争的最后几个月入伍。
jump at（及物，不可分）欣然接受，急于抓住
The tourists jumped at the guide's offer.游客们欣然接受了导游的提议。
The youngster jumped at the chance to go to college for further studies.这小伙子立刻抓住了这个上大学深造的机会。
jump on ［upon］（及物，不可分）斥责
The teacher jumped on an inattentive student.老师对一位不专心的学生严加指责。
His mother jumped on him for his dishonesty.他母亲严厉责备他的不诚实行为。
The boy was jumped on for being lazy.这男孩因为懒惰受到指责。