They learned about the offer of free goods at ______.

All the housewives who went to the new supermarket had one great ambition: to be the lucky customer who did not have to pay for her shopping. For this was what the notice just inside the entrance promised. It said: "Remember, once a week, one of our customers gets free goods. This may be your lucky day?
   For several weeks Mrs. Edwards hoped, like many of her friends, to be the lucky customer. Unlike her friends, she never gave up hope. The cupboards in her kitchen were full of things which she did not need. In vain her husband tried to dissuade her. She dreamed of the day when the manager of the supermarket would approach her and say: "Madam, this is your lucky day, Everything in your basket is free."
   On Friday morning, after she had finished shopping and had taken it to her car, she found that she had forgotten to buy any tea. She dashed back into the supermarket, got the tea and went towards the cash desk. As she did so, she saw the manager of the supermarket approach her. "Madam", he said, holding out his hand, "I want to congratulate you! You are our lucky customer and everything you have in your basket is free."