“Passengers _____ not have their breakfast on the light train”. This rule arouses heated debates in Chongqing.

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

His work _____ have been completed; otherwise, he wouldn’t be enjoying himself on the beach.

With the help of the smart phones, you ____ video chat with your friends on the phone.

Johnny, you _________play with the knife, you_________ hurt yourself.