In this section, you will hear one long conversation. At the end of the conversation, you will hear four questions. Both the conversation and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).A、The problem is on a regional scale.
B、The problem is on a worldwide scale.
C、The problem is on a national scale.
D、Not mentioned.