There is __________ “u” and __________ “n” in the word “unhappy”.
----- Your English is very good, who taught you?----- Nobody. I taught _____.
_____ he is ill, _____ he still goes to work.
-----_____ do you exercise?-----Once a week.
Which is _____, the sun or the moon?
Lily and Lucy are twins, they _____ good girls, they often help others.