您要查找的是不是：
- 倒U曲线inverse U curve
- “倒U曲线”假说"upside- down U curve" hypothesis
- 库兹涅茨倒U曲线Kuznets' reversed U curve
- 曲线(n) curved shape
- 倒U假说Inverted-U-Type Hypothesis
- u盘
- 倒U型特征converse U type characteristic
- 曲线的curvilinear
- 倒出swill
- 标准曲线specification curve
- 倒U型假说Inverted-U Hypothesis
- 曲线拟合curve fitting
- 倒掉outwell
- 倒档reverse gear
- 拟合曲线fitting curve
- 倒钩barb
- 特性曲线frequency plot
- 翻倒overturn
- 变化曲线change curve
- 倒过来the other way around
