Question 3 is based on the conversation you have just heard.

3. What does Professor Henderson say is a top priority in combating climate change?

解析：A。本题目为细节题。问题为：Henderson教授说对抗气候变化最重要的是什么？出题点位置在强调处（最高级）。正确选项原文所在句：As I said, we need to understand the best ways of avoiding climate change and this will involve a huge transition to low carbon energy systems. And the transition is a tremendous priority.我们需要了解避免气候变化的最佳方式，并且这涉及向低碳能量系统的巨大转变，而这种转换是最重要的。A) The transition to low-carbon energy systems（向低碳能量系统转变），与该信息完全一致。其他选项干扰性较弱。本题关键在于抓住关键词priority和low-carbon energy system。