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UID1520568在线时间 小时注册时间2022-6-4最后登录1970-1-1主题帖子性别保密 
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| main idea: origin of vertebrate structure:
 p1. introduces the question on the origin of vertebrate and theory
 -vertebrate - protochordate: t&l ➡️ controversy but similar in many ways
 -ancestor chordates: lack of organ system
 -advancements: sense organs/ muscle blocks➡️ swim/urine by filter blood/a large brain to store Information./metabolic capacity/tissue: bone/ endocrine organs/ kidney
 p2.natural selection favored the evolution
 -two more questions: in what environment & what forces determine
 
 new words:
 endocrine: 内分泌的
 tissue: 组织
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