The army organized teams to dig out those who were trapped and to bury the dead.
问题描述：
The army organized teams to dig out those who were trapped and to bury the dead.
这句话转换成：The army came to help - digging out trapped people,burying the dead and rescuing miners.
请从语法角度解释为什么这里dig,bury,reacue三个词转换后要变成ing 形式,
答
这个非谓语动词,句子中已有主语the army,已有谓语came to help,而后面要接动宾,由于主语the army 与 dig,bury,resue存在主动关系,所以用ing ,PS：如果表被动用done,表将来目的用to do动宾是？？？动词加宾语结构， 如句中的digging out 为谓语，trapped people是宾语,就是动宾结构