【正确答案】
B
【答案解析】[听力原文]18-20
Mr. and Mrs. Smith and their children were going to spend their holidays in the country. They had to be at the railway station before 11: 40 in the morning. "We'll have to be ready by 11 o'clock, or we'll be late." At 11: 10, they still weren't ready yet except Mrs. Smith. She was sitting quietly in a chair in the garden. Her husband and children were surprised that she was not in a hurry until the car arrived. Then Mrs. Smith smiled and said to them, "Well, before I went to bed last night, I moved our clocks and watches 20 minutes ahead!/