I rang you at about ten o’clock, but there was no reply. – Oh, that was probably ________ I was seeing the doctor.

This is ______ my pen. I’m writing with _____ pen.

How long have you been studying at this school?—I have been studying here_____. [ ]

Is this Tommy’s suitcase?— No, it is not . It is .

The boy is too young to go to school. [ ]