Use Blank Entity to blank any geometry entity.
To open Blank Entity:
Click Blank Entity (Geometry Tools toolbar) or click Geometry, Geometry Tools, Blank Entity .
In the dialog, you can blank specified types of entities by checking related filters.You can also blank/unblank all and reverse blank. When "Blank Independent" is checked, the independent shape will be blank. Such as selecting one face from a solid, the solid will be blank.
Blank All . Blank all geometry related entities in current model.
Unblank All. Unblank all geometry related entities in current model.
Undo Last. Undo last blank operation.