托福【模拟测试-6】-2017服务一体化 What is the talk mainly about?

在讲义文的开头部分，教授首先揭示了主题是有关山魈的内容。然后，他依次对山魈使用语言、触觉、视觉以及嗅觉的表达意思、相互交流的方式进行了说明。因此正确答案选C。讲义文也提到了尚未研究清楚的嗅觉交流方式，选择食物的习性以及生存地，但是这些都是细节性内容，不能作为正确答案。因此，A和B选项都不正确。 【对应原文】 Today, we're going to focus on the mandrill...the most colorful monkey-or rather, it's not truly a monkey anymore...it's been classified as its own genus, mandrillus-but yes, the most colorful of primates...the mandrill. They are social creatures and have been observed by scientists to live and travel in packs of, uh, up to eight hundred individuals! Can you imagine it? Normally though, it's anywhere between twenty and two hundred. The way mandrills communicate has been an interesting focus of research for scientists... they have several types of communication.