jackknife/ˈdʒæk.naɪf/名词大折刀/ˈdʒæk.naɪf/动词弯成V字形(如铰接货车的弯折)The oil tanker jackknifed after skidding on the ice.油罐车在冰上打滑,绞接的车身之间发生了弯折。想跟读,去练习