He likes to play ______ violin and I listen to _______ music.
––_______ have you been a volunteer? ––Since three years ago.
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.