number of strokes per minute

例句：

1. 1. The artist spent hours perfecting his painting technique.
   这位艺术家花了很多时间来完善他的绘画技巧。
2. 2. The teacher asked the students to count the number of strokes in their drawings.
   老师要求学生们数出他们画作中的笔画数量。
3. 3.The dancers performed a routine with a high number of strokes per minute.
   舞者们表演了一个每分钟有大量动作的舞蹈。