pin for suppressing metal

例句：

1. 1.The engineer pinned the machine to the wall to prevent it from moving.
   工程师将机器固定在墙上以防止其移动。
2. 2.The scientist pinned down the results of his experiments to ensure accuracy.
   科学家将他的实验结果钉下来以确保准确性。
3. 3. The painter pinned down the colors on the canvas to create a harmonious composition.
   画家在画布上钉下颜色以创造和谐的组合。