31. -- You haven't lost the ticket, have you?-- _________. I know it's not easy to get another one at the moment.
Many people agree that___knowledge of English is a must in___international trade today.
How beautifully she sings! I have never heard____.
If there were no examinations, we should have_____at school.
She is_____new comer to____chemistry but she has already made some important discoveries.
Shortly after the accident, two___police were sent to the spot to keep order.