He ____ not be in the room.I saw him on the playground just now. 用情态动词填空,

He ____ not be in the room.I saw him on the playground just now. 用情态动词填空,
He ____ not be in the room.I saw him on the playground just now. 用情态动词填空,

He ____ not be in the room.I saw him on the playground just now. 用情态动词填空,
用can 表示不可能,这个是比较确定的,因为他在操场上就不可能在屋子里了.
而这是过去时态,后面用的是saw可以看出.
所以用could,是can 的过去时态.

He could not be in the room.I saw him on the playground just now.
他不可能在房间里，我刚刚在操场上看见他。