number of friction pairs的用法和樣例：
例句
- Secondly, the performance of friction couples are tested under the condition of USM running.
接著在電機運轉的條件下，對耐磨材料組成的摩擦副的表現進行評價和優選。 - Results show that effect of temperature should not be neglected in researching the lubrication of cam-tappet pairs.
在對此類摩擦副進行潤滑研究時，不能忽略溫度因素的影響。
