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

—Why can your neighbor know so much about London?—He ____ have been there before.

—Have you checked the engine? —Yes, I did twice; there ______ be anything wrong with the car.

Though _______ money, his parents managed to send him abroad.

— May I smoke here?— No, you ________. Can’t you read the sign “NO SMOKING”?