听下面一段对话，回答1-4。 1. How do we pay the teachers? A. We pay them through taxes. B. We pay them directly. C. Some large factories pay them. 2 What is most of the public money used for? A. Protecting people and possessions. B. Paying the teachers and other public officials. C. Teaching and training our citizens. 3 How did the government raise money in the past? A. By selling services that make life comfortable. B. By selling coal and other natural products. C. By selling public lands. 4 What is the passage mainly about? A. Environmental pollution and protection. B. Taxes and services for the public. C. Police efforts to protect people.