题目原文：
Animal fossils usually provide very little opportunity to study the actual animal tissues, because in fossils the animals’ living tissues have been largely replaced by minerals. Thus, scientists were very excited recently when it appeared that a 70-million-year-old fossil of Tyrannosaurus rex (T. rex), a dinosaur, might still contain remains of the actual tissues of the animal. The discovery was made when researchers deliberately broke open the T. rex’s leg bone, thereby exposing its insides to reveal materials that seem to be remains of blood vessels, red blood cells, and collagen matrix.
First, the breaking of the fossilized leg bone revealed many small branching channels inside, which probably correspond to hollows in the bones where blood vessels were once located. The exciting finding was the presence of a soft, flexible organic substance inside the channels. This soft substance may very well represent the remains of the actual blood vessels of T. rex.
Second, microscopic examination of the various parts of the inner bone revealed the presence of spheres that could be the remains of red blood cells. Tests showed that the spheres contained iron-a material vital to the role of red blood cells in transporting oxygen to tissues. Moreover, the spheres had dark red centers (substances with iron tend to be reddish in color) and were also about the size of red blood cells.
Third, scientists performed a test on the dinosaur leg bone that showed that it contained collagen. Collagen is a fibrous protein that is a main component of living bone tissue, in which it forms a so-called collagen matrix. Collagen (or its chemical derivatives) is exactly the kind of biochemical material that one would expect to find in association with bone tissue.
题目音频：
学术写作：
教授：当下大学主要是学科类这种，而未来的教育是否更多是短期考证项目？
Kelly：短期考证。因为更适应现在很多人想要换专业。
Andrew：还是传统的学科专业类这种。学习更深入，未来收益更高。
Doctor Achebe: This week, we’ll be discussing the future of education. Let’s focus now on the following viewpoint: it is no longer useful to spend many years pursuing a traditional, specialized university degree in a single field, such as communications or economics. Instead, it makes more sense for most people to complete several shorter certification programs and earn certificates in, for example, project management, computer programming, graphic design, and so on. Do you agree or disagree with this viewpoint? Why?
Kelly: I strongly support this approach because it aligns with the changing preferences of many individuals in the modern world who often wish to switch majors or career paths. Embracing certification programs allows people to explore and pursue the fields they are passionate about without the commitment of lengthy degree programs.
Andrew: University education is a superior choice due to its comprehensive and specialized nature. While certification programs offer quick training, universities provide a more in-depth understanding of a subject. They encourage critical thinking, research skills, and a broader knowledge base. University degrees often lead to higher earning potential and career opportunities.
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