关与英语的N道题Thestory_____inthenineteenthcentury.a.washappenedb.happenedc.hashappenedd.hasbeenhappenedTheairinbigcities_____often_____verydirtybyfactories.a.is,madeb.are,madec.will,maked.will,madeTheoldman

问题：关与英语的N道题Thestory_____inthenineteenthcentury.a.washappenedb.happenedc.hashappenedd.hasbeenhappenedTheairinbigcities_____often_____verydirtybyfactories.a.is,madeb.are,madec.will,maked.will,madeTheoldmanwasseriousl

答案：↓↓↓

程振轩的回答：

网友采纳　　b.happened　　a.is,made　　sendfor派人去请...　　a.wouldtakepartin　　b.tosave不定式做表语