I called several times,but couldn't ___you

I called several times,but couldn't ___you I rang you several times but couldn‘t’ get through主语是啥 I rang the doorbell several times but couldn't __anyone hear I rang the doorbell several times but couldn't ___ anyone he I tried to ___you at home several times,but no one answered i've told him several times but he____doesn't understand telephone number several times,but he couldn't learn it by h I called you several times last night ,but there was no answ Where were you last night?I called you several times but cou Told several times, he couldn't understand what I meant. 为什么 ____ to go for a walk,but someone called and I couldn’t get I 've told him several times but he ____ doesn't understand