He ____ writing the paper now. He hadn’t written a single word when I left him ten minutes ago.
A、shouldn’t be B、can’t have finished C、can’t be D、mustn’t have finished
He ____ writing the paper now. He hadn’t written a single word when I left him ten minutes ago.
A、shouldn’t be B、can’t have finished C、can’t be D、mustn’t have finished
B
考查情态动词。“can’t have + 过去分词”表示对过去情况的可能性推测，此处意为“不可能已完成”。