backward ray cone

例句：

1. 1.The car was moving backwards in the snow.
   汽车在雪中倒退。
2. 2. He turned around and saw the dog was backing up.
   他转身看到狗正在倒退。
3. 3. The team is trying to reverse the game's course.
   球队正试图改变比赛的局势。