转折原则 What does the professor imply about the design of research experiments that the students might conduct on bird navigation? A.Well-designed research studies help to explain human as well as bird navigational abilities. B.Past research studies were mistakenly designed to study only one navigational skill at a time. C.Students need to be careful to avoid designing experiments that are based on faulty assumptions. D.Students should try to design experiments that challenge traditional theories about birds' navigational abilities. 听力原文： I mean even with maps, how often do we get lost? 我意思是，即使有地图，我们还是会经常迷路。 But with birds, they're actually over engineered to be good at navigation. 但是对于鸟类，它们实际上有很多设计，用来擅长导航。
在托福听力部分，信息通常以一种逐渐扩展的方式呈现。除了转折的关系外还包括举例子、对比不同观点、提出假设或者解释原因等。因此，大家可以通过在练习中着重于这些关系，逐渐培养出预测信息发展方向的能力。
重复原则
在托福听力考试中，通常会选择多次提及的内容作为出题点。因此听力中的重复信息是暗示考生要关注这些内容，并表明答案可能与这些重复出现的要点相关。
重复原则常常发生在特定的上下文语境中，比如教授在介绍一个新的术语或观点时，会在后续利用例子或更详细的论述去解释。
Why does the professor mention a study with gannets? A.To identify a bird species that does not migrate long distances B.To explain that some birds fly in spiral patterns until they locate food sources C.To illustrate differences in behavior between coastal and mountain bird species D.To demonstrate that some birds use distinctive features of the landscape as a navigation tool 听力原文： Student: Well, for short distances, you could just memorize the area, use landmarks, like when my friend tells me to turn left after I see the post office to get to his house. 学生：对于短距离，你可以只需记得这区域里，利用地标，比如我的朋友告诉我在看到邮局后左转去他家。 Professor: So when birds are out searching for food, they can memorize landmarks: mountains, rivers, who knows, maybe even the post office. 教授：所以当鸟出去寻找食物时，它们可以记住地标：山脉、河流，甚至可能是邮局。 Studies of gannet have shown that this is one way they navigate. 对塘鹅的研究表明，这就是它们导航的一种方式。
男生说短途的话，鸟可以记住地形landmark来回巢。professor认可这种说法，并且在后面举例gannets来说明它们海岸线来导航回巢，对应D选项。
强调原则
虽然在托福听力考试中获得想要的分数可能很有挑战，但是经过认真地备考和不断的练习，小曼老师相信大家一定会有所进步~