本文难点：复杂的场景词汇和生僻的背景知识;
本文有效词汇摘选
1) infrasound n. [物] 次声(风暴产生的低频音波)
2) acoustical spectrum: 声谱
3) ultrasound n. 超声(波)
4) self-explanatory adj. 自明的，不需加以说明的
5) filtering v. 过滤，筛选
6) ground clutter 地面反射波，地面杂乱回波
7) jagged adj. 锯齿状的，参差不齐的
8) navigation andorientation 航海和定向
9) emit 发出
10) pulse 脉冲
11) bounce back 反弹;迅速恢复活力
12) bursts of sound 突然发出声音
13) moth 蛾子
14) motionless 静止不动
15) beating theirwings 扇动翅膀
16) spear-nosed bat 叶口蝠;矛吻蝠
17) acoustical 听觉的
18) squad 限于小分队
19) deciduous tree 落叶树
20) oaktree 橡树
本文每题目和考点分析：
学习方法要求—建议学员将考点分析的原文部分做多遍跟读模仿，之后熟练背诵
第一题考点解析：
Now, let’s talk about the other on the acoustical spectrum, sound that’s too high for humans to hear---ultrasound. Ultrasound isused by many animals that detect and some of them send out very high frequency sounds. So, what’s a good example?(开头引出主旨，特别注意一些如today, now, ok, well, so等词汇的应用)开头听完做好预测，听完此部分的最后一句，最好对下文做好文章结构的预测：本文为例子对应观点的现象解释型文章结构。
第二题考点解析：
You know, I don’t think I need to draw the echoes, your reading assignment for the next class, it has a diagram that shows this very clearly.(you know在托福听力中的考点经常为，进一步解释说明和例证说明)
第三题考点解析：
For example, one echo they quickly identify is one way associate with moth, which is a common prey for a bat, particularly amoth beating its wings. However, a moth happened to have a major advantage over most other insects. They can detect ultrasound; this means that when a bat approaches, the moth can detect the bat’s presence. So, it has time to escape to safety, or else they can just remain motionless.(例子对应观点，例子在被充分展开解释后，要关注的细节为：1. 例子和其例证观点的对应关系;2. 例子被强调解释的细节部分。本题的细节考点在So之后，同学们请多多注意“so”在托福听力中的作用)