You can select certain layers and hit Control+Alt+B to set your work area to the duration of those layers, or if no layers are selected it will reset the work area to the entire comp.

你还可以选择某一层，按Ctrl+Alt+B设定工作区域和这个层一样，如果没有选中层，则工作区域被设定为整个合成的长度。

youdao

You can select certain layers and hit Control+Alt+B to set your work area to the duration of those layers, or if no layers are selected it will reset the work area to the entire comp.

你还可以选择某一层，按Ctrl+Alt+B设定工作区域和这个层一样，如果没有选中层，则工作区域被设定为整个合成的长度。

youdao