请问All buses ((having been canceled)) because of the heavy snow,they had to to there on foot.
All buses ((having been canceled)) because of the heavy snow,they had to to there on foot.
括号里的((having been canceled))能不能替换为canceled
我还问问,从句中动词的被动形式可以与动词的名词形式一样用,而不需要加be动词吗?