第一篇讲座：
讲了传统能源，还有一种新的能源methane晶体在海里，随着全球变暖对海水造成影响。
词汇：
crystal英['krɪst(ə)l] 美['krɪstl] n. 结晶，晶体
第二篇讲座：
艺术学——讲的是美国风景画的发展
相关背景知识补充：
Landscape art is the depiction in art of landscapes, natural scenery such as mountains, valleys, trees, rivers, and forests, and especially art where the main subject is a wide view, with its elements arranged into a coherent composition. In other works landscape backgrounds for figures can still form an important part of the work. Sky is almost always included in the view, and weather is often an element of the composition. Detailed landscapes as a distinct subject are not found in all artistic traditions, and develop when there is already a sophisticated tradition of representing other subjects. The two main traditions spring from Western painting and Chinese art, going back well over a thousand years in both cases. Landscape photography has been very important since the 19th century, and is covered by its own article.
The recognition of a spiritual element in landscape art is present form its beginnings in East Asian art, drawing on Daoism and other philosophical traditions, but in the West only becomes explicit with Romanticism.
第二篇对话：
女生第二天去办公室说她错过了play很沮丧，说明了原因，还有一些安慰。
第三篇讲座：
鸟类翅膀的变化，可能是一种龙的进化，给了两个hypothesis后来又反驳了，再新给了一个hypothesis.
解析：
词汇：
evolution 英[,iːvə'luːʃ(ə)n; 'ev-] 美[,ivə'luʃən] n. 演变;进化论;进展
hypothesis 英[haɪ'pɒθɪsɪs] 美[haɪ'pɑθəsɪs] n. 假设
refute 英[rɪ'fjuːt]美[ri'fjʊt] vt.反驳，驳斥;驳倒
第四篇讲座：
考古学，讲的是洞穴里的一些记号和文字的由来和原因及其符号之间的联系。
解析：相关背景知识
Cave paintings are paintings found on cave walls and ceilings, and especially refer to those of prehistoric origin. The earliest such rock art in Europe dates back to the Aurignacian period, approximately 40,000 years ago, and is found in the El Castillo cave in Cantabria, Spain. The exact purpose of the paleolithic cave paintings is not known. Evidence suggests that they were not merely decorations of living areas since the caves in which they have been found do not have signs of ongoing habitation. They are also often located in areas of caves that are not easily accessible. Some theories hold that cave paintings may have been a way of communicating with others, while other theories ascribe a religious or ceremonial purpose to them.