speed hang up

例句：

1. 1. The car accelerated to a speedof 60 miles per hour.
   汽车以每小时60英里的速度加速。
2. 2. Theracers need to maintain their speed forthe last lap.
   赛车手需要保持最后一圈的速度。
3. 3. The train will reach its destinationin half an hour if it keeps upits speed.
   如果火车保持其速度，它将在半小时内到达目的地。