----I’m worried that I don’t know how ___the work.----Don’t worry! Why not ___the teacher for help.
He has been collecting coins _______ he was seven years old.
She is usually _______. Why did she get ill so suddenly?
Because of Project Hope (希望工程), _______ children have better lives.
––Has your brother ever been to the Sand Lake? ––Yes, he has _______ the Sand Lake many times.
This morning my mother asked me__.