[threatened]threatened by

Threatentodo，威胁做某事，中间不加sb而threatsbintodoing威胁某人做某事；是过去分词，不是过去式。原句写法有错误，有成分的缺失，缺少be动词，正确写作It主语is系threatenedtosurroundhimcompletely表可表达“它被威胁