fall-off减少;衰减;尖削度;尖削
fall-off test压降试井
capacity fall-off电容量减退
fall-off resistance跌落电阻
fall-off voltage跌落电压
isodose fall-off等剂量下降;剂量跌
fall angle off factor渐疏因子
Fall not off不要被压向下风
fall l off跌落;衰退;掉下
PHRASAL VERB（动词词组） If something falls off, it separates from the thing to which it was attached and moves toward the ground. 脱落
When your exhaust pipe falls off, you have to replace it.
当你的排气管脱落时，你只能更换它。
PHRASAL VERB（动词词组） If the degree, amount, or size of something falls off, it decreases. 降低; 减小
Unemployment is rising again and retail buying has fallen off.
失业率又在上升，而零售购买量已经减少。