at a run

例句：

1. 1.She ran to the store as soon as she heard the news.
   她一听到消息就跑去商店。
2. 2. The car was moving at a run when it hit the guardrail.
   汽车在撞上护栏时正以高速行驶。
3. 3. They were running late for their meeting.
   他们开会迟到了。