被动语态的构成：be+过去分词
一般现在时 am / is / are +过去分词
一般过去时 was / were +过去分词
一般将来时 shall / will + be +过去分词
过去将来时 should / would + be +过去分词
现在进行时 am / is / are + being +过去分词
过去进行时 was / were + being +过去分词
现在完成时 have / has + been +过去分词
过去完成时 had been +过去分词
情态动词 情态动词+ be +过去分词
