Since then,it_______every 4 years.为什么填is held而不是has been hel

Since then,it_______every 4 years.为什么填is held而不是has been hel 英语翻译.and have been held every four years since then.是关于奥运会的h It is 3 years since he joined the army.为什么用is不用has been It is the worst weather since 50 years ago为什么不是It has been.不 it is 3 years since Tom has been abroad It has been 4 years since I smoked.为什么翻译成 我戒烟4年了? It has been 4 years since I smoked.怎么翻译? It has been 4years since I smoked. 为什么是he has been dead for 10 years而不是he has dead for 10 years Tom got sick last May and has been in bed since then.为什么has It has been years since I returned home,为什么since用,而不用when?分不 it is two years since I came here还是it has been two years sin