Question: Using the examples from the lecture, explain the professor's main point about Batesian mimicry and its effectiveness.
🎧 听力讲座
Today we're going to discuss a fascinating aspect of animal behavior known as 'biological mimicry' — where one species evolves to resemble another for survival. Specifically, I want to focus on a type called 'Batesian mimicry', where a harmless species mimics a dangerous or unpalatable one to avoid predators. The key point is that this mimicry only works if the mimic is less common than the model, because predators must first learn to avoid the dangerous model. Let me give you two examples. First, consider the scarlet king snake, which is harmless, but its red, yellow, and black bands closely resemble the venomous coral snake. Predators that have had a bad experience with coral snakes will avoid the king snake too. However, in areas where coral snakes are rare and king snakes are abundant, predators may not learn the association, and the mimicry fails. Second, think of certain harmless hoverflies that mimic the yellow and black stripes of stinging wasps. Birds that have tried to eat a wasp quickly learn to avoid anything with those stripes. So, the hoverfly benefits, but only if wasps are plentiful enough in the environment to teach predators the lesson.
📝 参考答案
托福口语 Task 4 评分标准
内容准确性(Content Accuracy):是否准确复述教授的主要观点
信息完整性(Information Completeness):讲座中的例子和关键细节是否完整
语言运用(Language Use):语法、词汇、表达准确性
表达(Delivery):流利度和清晰度
总分30分,原始分0-4分,最终换算为30分制。
答题技巧
听讲座时快速记笔记,抓住主要观点和两个例子
用20秒准备时间组织回答结构
回答时先点明教授的主要观点,再用例子解释
使用模板句式:"The professor explains... For example..."
控制在60秒内完成回答
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