It is partly ______ the summer day is longer that everything has a larger time to warm up.
Only when he had done it ______ that he had made a mistake.
---Would you mind if I opened the door? --- ________________.
It is demanded that you ____ at six.
At present,there is little doubt ________ short message plays an increasingly important role in our lives.
— Are you a teacher? — No, but I ______. I worked in a middle school for three years.