speed at instant of contacts separating

例句：

1. 1. The car accelerated to 60 miles per hour on the highway.
   汽车在高速公路上以每小时60英里的速度加速。
2. 2. The project will increase the speed of data transmission.
   该项目将提高数据传输的速度。
3. 3. The train is moving at a steady speed.
   火车正以稳定的速度行驶。