David didn’t give up ______ he had failed in the experiment four times.
--______of sport do you do every week? –One or two hours.
–How often do you go to the movies? --___________.
He always goes to school early and he is _________late for school.
--________does your father exercise? –Three times a week.
–What did you do on your uncle’s farm? --I _______the horse and _______some hens there.