楼主并不提供详细翻译喔，由于篇幅和时间精力的限制，所以楼主只粗略说明，如果有疑问，请大胆地提出来^__^楼主会在自己的能力范围内尽可能给出详细解答的~ Study notes -- Episode 5 Global Warming 本期的知识点是～USING REFERENTS
Referents are words, which refer back to something that has been mentioned before. They not only add variety to your writing and speaking, but also provide cohesion to what you write or say. Using referents means you can avoid repetition, and make your writing more interesting, easier to read and understand. Remember, when using pronouns as referents, it is important to identify clearly to what the pronoun refers in your sentence, paragraph or essay. This is to avoidambiguity.
The shark is a carnivorous (meat-eating) sea mammal. It is one of the most feared fish in the ocean, having the reputation of attacking humans. There are many species that roam the great oceans of the world. ①They vary in size and habit. Though the whale shark is considered the largest, it is relatively harmless, and mainly eats small fish and plankton. Other sharks include the hammerhead, mako and bull. ②These are fast, powerful sea animals that feed on larger fish such as mackerel, tuna and herring. The white shark, on the other hand, is the most frightening and dangerous. It gets ③this reputation because of ④its size and keen sense, which enables it to prey successfully. Since the early 1960’s, scientists have been studying sharks because of their potential to provide the medical world with defences against diseases such as cancer and arthritis. That would be welcomed by all.