2 sentences for 变速 (biàn​sù)

1. 这种变速电钻可以根据不同的材料调整转速。

   zhè zhǒng biàn​sù diàn​zuàn kě​yǐ gēn​jù bù​tóng de cái​liào tiáo​zhěng zhuàn​sù.

   This variable-speed drill can be adjusted for different materials.

   Source: Dong Chinese Dictionary

2. 运动员在赛跑的最后阶段突然变速，冲向终点。

   yùn​dòng​yuán zài sài​pǎo de zuì​hòu jiē​duàn tū​rán biàn​sù, chōng​xiàng zhōng​diǎn.

   The athlete suddenly accelerated in the final stretch and sprinted toward the finish line.

   Source: Dong Chinese Dictionary