She bought the same skirt at a lower price at the same shop where I bought mine because she was a __________ customer.
Mary often helps her best friend, ______ math is very poor.
Beijing is _____ capital of _____ China.
To be able to catch up with the other students, he needs ___ hard work; he needs your encouragement, too.
___ you have finished your homework, you can go and play with your friends.
She knows so much about England. She ___ there before.