---What do you think is the matter with your car? ---Well, it _____ start at all. I mean I turned the key and nothing happened. 

_____ you tell me how to use this digital dictionary?

—Can we leave the classroom now?—No, you _________. You _________ to leave until the bell rings.

Sometimes smiles around the world ________ be false, hiding other feelings like anger, fear or worry.

---I think Miss Gao must be in the library. She said she would go there. ---No, she ___________ be there. I have just been there.