单项选择题

Directions:
You will hear three dialogues or monologues. Before listening to each one, you will have 5 seconds to read each of the questions which accompany it. While listening, answer each question by choosing A, B, C or D. After listening, you will have 10 seconds to check your answer to each question. You will hear each piece once only.
Questions 11—13 are based on the following passage. You now have 15 seconds to read Questions 11—13. In the USA, how many children smoke every day