It is not socially ____for parents to leave children unattended at that age.
He was told that it would be at least three more months ______ he could recover and return to work.
To their surprise, they found the lecture given by the famous professor easy ______.
It was the first time ________ I ________ face to face with a thunder storm.
Hurry up! The train______. You know it______ at 8:30 am.
He spoke about the country as if he had been there, but ________ he had never.