Mr and Mrs Smith have just opened a small restaurant. In order to _  , they put a notice in front of the restaurant, which said " Meals on the House for Three Days." A foreign student who didn't know much English happened to pass by the restaurant on the second day. It was lunch time and he felt very hungry. "Well, here is a restaurant. I am going to have something to eat." He walked towards the restaurant when he saw the notice. " American people are really strange. They even eat dinners on the house! But how can I get up to the top of the house?" he said to himself. He looked around and found a ladder  against a tree nearby. He was very glad. But as he reached the top he heard someone shouting at him. " Hey, what are you doing up there?" Mr Smith was looking at him angrily and beside him was a policeman. " Don't your notice say " Meals on the House for Three Days"? Is it just a joke?" the foreign student answered. On hearing this, both Mr Smith and the policeman laughed. " Don't you know what ON THE HOUSE means? Look it up in the dictionary," the policeman said. The story happened in   _  .
the USA Canada England Australia