• 在黑板上

onprep.在 ... 之上；由 ... 支撑着；在（某一天）；关于；基于adv.穿着；向前（移动)；表示持续性adj.表示已连接、处于工作状态或使用中；发生；值班Onahaman.小名滨(在日本；东经 140º53' 北纬 36º58')

1. The boy stole from classroom while the teacher was writing on the blackboard.
   老师在往黑板上写字时，那孩子偷偷溜出了教室。
2. He took out a piece of chalk and wrote his problem on the blackboard.
   他拿出了一支粉笔并在黑板上写下他的问题。
3. The teacher wrote down the new words on the blackboard.
   老师在黑板上写出新单词。
4. The teacher wrote on the blackboard with a piece of chalk.
   老师用一支粉笔在黑板上写字。