把…披／搭／蒙在…上
to put something such as cloth or a piece of clothing loosely over something
He draped his jacket over the back of the chair and sat down to eat. 他把夹克衫搭在椅子靠背上，然后坐下来吃饭。
She draped the scarf loosely around her shoulders. 她把围巾松松地披在肩膀上。
He'd draped the flag around himself after winning the race.
She had a red sweater draped elegantly across her shoulders.
Why not drape the blanket over the back of the sofa?
See also: drape verb