— Who helped you clean the classroom yesterday?— Nobody. I did it all by ____.
-What’s his brother? -He is a teacher.He__________ maths at a school.
-Help yourself to some more meat,Linda. -_______________.
-Do you need my help, Mary? -_____________.
-Hello,Jack.How are you doing? -__________.
-When was David born? -He was born________June 12,1989.