checking of redundant substance

例句：

1. 1.The manager is checking the inventory before the meeting.
   经理在会议前正在检查库存。
2. 2.The student checked his answers and realized he had made a mistake.
   学生检查了他的答案，意识到自己犯了一个错误。
3. 3. The police are conducting a thorough checking of the crime scene.
   警方正在对犯罪现场进行彻底的检查。