<-NARRATOR:->Listen to a conversation between a student and his geography professor.

旁白：请听下面一段学生与他的地理教授之间的对话。

<-MALE STUDENT:->Hi, Professor Brown.

学生：您好，布朗教授。

<-FEMALE PROFESSOR:->Hi, Paul. What can I do for you?

教授：你好，保罗。需要帮助吗？

<-MALE STUDENT:->I have a question about the final exam … I mean, will it cover everything we’ve done all term, or just what we’ve been doing since the midterm exam?

学生：我有个关于期末考试的问题。我是说，考试的内容包括我们这学期所有的知识吗？还是期中考试以后我们学的知识？

<-FEMALE PROFESSOR:->Everything we’ve done all term.

教授：我们这个学期学的所有的知识。

<-MALE STUDENT:->[Not very happy about that]Oh, boy. You know, I’m still not too clear about the hydrologic cycle, um … the transfer of water back and forth between the Earth and the atmosphere …I really blew the question about it on the midterm exam. I wanna do better on the final exam, but I’m still having trouble with it.

学生：哦，天啊。有关水循环的问题我还不是很清楚，嗯，就是水在地球和大气之间的循环。在期中考试的时候我这个问题就回答的一塌糊涂，我希望在期末考试中能答好这个问题，但是我还是不太明白。

<-FEMALE PROFESSOR:->[Sympathetic]Well—um, have you been to the tutoring center?

教授：这样啊，你去过辅导中心吗？

<-MALE STUDENT:->No, not for geography anyway. Isn’t that just for when you need help with writing … like an essay or a research paper?

学生：没有，没去过地理课的辅导中心。那里不是只有当你写论文或研究报告的时候需要帮助的时候才能去吗？

<-FEMALE PROFESSOR:->Oh, no. You can get tutoring in a lot of subjects. Some graduate students from this department tutor there.

教授：哦，不。很多问题你都可以得到辅导。有许多地理系的研究生会在那里给大家辅导。

<-MALE STUDENT:->Um, that’s good to know, but I hardly go there because I have a part-time job. I never seem to be free when they’re open.

学生：得到这个消息很高兴，但是我很少去那里，因为我要做兼职。那里开的时候我总没有时间。

<-FEMALE PROFESSOR:->Well, they’ll be extending their hours when final exams begin—you might try then.But um…Well since you’re here now, can I help you with something?

教授：哦，期末考试的时候他们会延长辅导的时间，你可以去那里试试。但是，既然你已经来了，我可以帮你看一下，哪里不会？

<-MALE STUDENT:->Well, the hydrologic cycle …I remember we went over a diagram in class … and from what I remember … water changes back and forth from water in lakes and oceans to vapor, and then back to water again when it falls as rain or snow … as precipitation.It’s constantly being recycled, through evaporation and condensation.

学生：太好了，是水循环。我记得课堂上我们讲过一个图表，根据我的记忆，水是来回循环的，湖水和海水变成水蒸气，然后水蒸气又变成雨或雪落下，也就是降水。他们不断的通过蒸发和液化循环。

<-FEMALE PROFESSOR:->[Not sure what the problem is]That’s it, basically. Umm … so exactly what is it you don’t understand?

教授：基本上就是这样。嗯，那你到底哪里不明白呢。

<-MALE STUDENT:->[Realizing he has to ask a more specific question] OK. I guess what I’m really confused about is how the topography of the land —the mountains and valleys and stuff—affect precipitation.

学生：我想我感到困惑的是地形是如何影响降水的，比如说山脉和峡谷或者是其他的地形。

<-FEMALE PROFESSOR:->OK, good question … Precipitation is influenced by topography, among other things. Uhh, why don’t we talk about lake-effect snow...It’s a phenomenon that occurs anywhere you have a large lake that doesn’t freeze, and has cold air flowing over it.Mostly in the Northern Hemisphere.

教授：嗯，问得好。降水除了其它方面也受地形影响。不如我们来讲一下大湖效应？这种现象发生在面积大的不结冰的湖区，湖区的上空有冷空气。而这种现象多在北半球出现。

<-MALE STUDENT:->Like the Great Lakes in the United States?

学生：就像美国的五大湖区？

<-FEMALE PROFESSOR:->Yes. What happens is that the cold, arctic air blows across the lake from the north in winter, and as the air crosses the lake, the lower layer is warmed by the lake water, which is much warmer than the arctic air.And as this layer is warmed and picks up moisture, it becomes lighter than the air above it …

教授：对！冬天北极地区的冷空气会从北边吹来，当冷空气穿过湖区时，低处的空气层会因湖水的温度而变暖，湖水比北极的冷空气要热的多。由于低处空气变暖湿度增加，与上层的空气相比它会变轻。

<-MALE STUDENT:->So it starts to rise, right?

学生：所以它就会上升，对吗？

<-FEMALE PROFESSOR:->Yes. And clouds begin to form.When the air gets close to the shore, it’s slowed down by the land, and starts to pile up.So it rises even faster, because it has nowhere else to go.That’s where topography comes into the picture.

教授：是的。所以会形成云层。当空气到达湖的边缘时，由于陆地的原因它的速度会减慢并不断聚集。所以它上升的更快，又无法到别的地方去。这就是地形造成的。

<-MALE STUDENT:->[Happy he knows the answer]And then it snows because as the air rises, it cools off and loses its capacity to hold water vapor.

学生：所以接着就会下雪，因为随着空气的上升，云层冷却并且失去了对水蒸气的控制。

<-FEMALE PROFESSOR:->That’s right.

教授：对！

<-MALE STUDENT:->OK, thanks. Any chance you’ll ask this question on the final?

学生：考试的时候您会出这道题吗？

<-FEMALE PROFESSOR:->[Laughing] I don’t know yet … but you seem to have a handle on it.

教授：这我还不知道，但是就算出了你也没有问题了。