题目原文：
Endotherms are animals such as modern birds and mammals that keep their body temperatures constant. For instance, humans are endotherms and maintain an internal temperature of 37°C, no matter whether the environment is warm or cold. Because dinosaurs were reptiles, and modern reptiles are not endotherms, it was long assumed that dinosaurs were not endotherms. However, dinosaurs differ in many ways from modem reptiles, and there is now considerable evidence that dinosaurs were, in fact, endotherms.
Polar dinosaurs
One reason for believing that dinosaurs were endotherms is that dinosaur fossils have been discovered in Polar Regions. Only animals that can maintain a temperature well above that of the surrounding environment could be active in such cold climates.
Leg position and movement
There is a connection between endothermy and the position and movement of the legs. The physiology of endothermy allows sustained physical activity, such as running. But running is efficient only if an animal’s legs are positioned underneath its body, not at the body’s side, as they are for crocodiles and many lizards. The legs of all modern endotherms are underneath the body, and so were the legs of dinosaurs. This strongly suggests that dinosaurs were endotherms.
Haversian canals
There is also a connection between endothermy and bone structure. The bones of endotherms usually include structures called Haversian canals. These canals house nerves and blood vessels that allow the living animal to grow quickly, and rapid body growth is in fact a characteristic of endothermy. The presence of Haversian canals in bone is a strong indicator that the animal is an endotherm, and fossilized bones of dinosaurs are usually dense with Haversian canals.
题目音频：
学术写作：
教授：社交媒体平台应该是政府监管还是平台自己监管？
Andrew：自己监管。
Claire：政府监管。
Doctor Gupta: We have read studies that explain the negative impact of social media on both children and adults. Many believe that social media will remain widely used in the future, since it is both popular and useful in some contexts, but because of the problems it poses, it should be regulated in some way. In your opinion, should governments regulate social media platforms, or should social media companies requlate their platforms themselves? Why do you think so?
Andrew: I believe social media companies should regulate themselves. There are plenty of social media platforms on the market, so the competition is tough. For example, to appeal to parents, a socia media platform could publicize that they have stringent regulations for children’s use of the platform, and in this way it could attract more users who care about children’s safety.
Claire: Social media companies should be taking an active role in combatting the negative effects, but that is not really happening. l hear many stories of false information spreading around, sometimes causing irreparable damage to people’s reputations. Therefore, the government should put stricter regulations on the companies, and they should be punished for not following the rules.
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