close-ratio two-speed motor

例句：

1. 1.The company's performance closely ratios to the industry average.
   该公司的业绩与行业平均水平紧密相关。
2. 2.The new product has a close-ratio of 80% to the previous model.
   新产品的紧密比率为80%，与前一代产品相似。
3. 3.The tighter the close-ratio, the more likely it is that the system will fail.
   紧密比率越紧，系统失败的可能性越大。