line parallel to the profile plane

例句：

1. 1. The line of cars on the road is moving slowly.
   路上的汽车线缓慢移动。
2. 2. The engineer drew a line on the map to indicate the route.
   工程师在地图上画了一条线来指示路线。
3. 3. The teacher drew a line between the two answers.
   老师在两个答案之间画了一条线。