Listening: The prof. talks about his own experience. Years ago, he and his wife went for a trip in an island. Unluckily, it rained all day, so they had no chance to explore the beach. Since then, whenever they plan to travel, her wife never wants to go to the island again, even though the prof. has checked that it doesn't rain that so often.
5. Listening: The man has a problem. This year is his calculus prof.'s first teaching. He isn't used to his way of explaining... The prof. teaches too fast, he gets confused. Two solutions: 1. He says he can switch to another calculus section, but has to take it in the evening when he wants to do homework or hang out with friends. 2. He also says he can organize a study group to discuss what they learnt after class. But it'll cost extra time.
6. Lecture: The topic is the two benefits of (忘了)。说的是，哺乳类动物哺育后代行为，就是母兽可能离开小崽子一会儿。俩好处：1. safety benefit. Take deer for example. Deer hide their young in the high grass and only check the nest once a day, because they check the nest too often, it'll be easily found by the predators. 2. The second benefit is that the young don't need to be fed too often(这是我记得的，感觉不太像好处。。。). For example, the milk of the rat is rich in nutrients. The young just need to have a little and that's enough... (现在感到越来越奇怪，同志们再去参考下别人的吧。。。)
