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- These primitive mammals were tiny and are thought to have been nocturnal. 这些原始哺乳动物是微小的和被认为是夜的。
- The common cavity into which the intestinal, genital, and urinary tracts open in vertebrates such as fish, reptiles, birds, and some primitive mammals. 泄殖腔脊椎动物（如鱼、爬行动物、鸟和某些低级哺乳动物）的肠道、生殖道和泌尿道口通往的共用体腔
- The common cavity into which the intestinal,genital,and urinary tracts open in vertebrates such as fish,reptiles,birds,and some primitive mammals. 泄殖腔脊椎动物（如鱼、爬行动物、鸟和某些低级哺乳动物）的肠道、生殖道和泌尿道口通往的共用体腔。
- archaic forms of life; primitive mammals; the okapi is a short-necked primitive cousin of the giraffe. 原始的生命形式；原始哺乳动物；短颈的俄卡皮鹿是长颈鹿的原始近亲。
- the most primitive mammals comprising the only extant members of the subclass Prototheria. 最原始的哺乳动物，组成原兽亚纲唯一的现存种类。
- Mammals arose from a fairly primitive reptile in the Mesozoic era. 哺乳类起源于中生代宛若原始的爬虫类。
- archaic forms of life; primitive mammals; the okapi is a short-necked primitive cousin of the giraffe 原始的生命形式；原始哺乳动物；短颈的俄卡皮鹿是长颈鹿的原始近亲
- the most primitive mammals comprising the only extant members of the subclass Prototheria 最原始的哺乳动物，组成原兽亚纲唯一的现存种类
- A whale is no less a mammal than a horse is. 鲸鱼和马一样都是哺乳动物。
- His art is primitive and provincial. 他的艺术原始而粗野。
- Primitive people often lived in caves. 原始人常常住在山洞里。
- The whale is the largest mammal in creation. 鲸是世上最大的哺乳类动物。
- Primitive peoples deified the sun. 原始部落将太阳奉为神。
- They built a primitive shelter out of tree trunks. 他们用一些树干建造了一个简陋的棚子。
- A corresponding organ in other mammals. 胸脯其它哺乳动物的相应器官
- Primitive man made tools from sharp stones and animal bones. 原始人用尖石块和动物的骨制造工具。
- A primitive hand-turned grain mill. 手推磨一种原始的手推碾谷磨
- archaic forms of life;primitive mammals;the okapi is a short-necked primitive cousin of the giraffe. 原始的生命形式;原始哺乳动物;短颈的俄卡皮鹿是长颈鹿的原始近亲。
- The book is about the mythologies of primitive races. 这本书是原始民族神话集。
- Primitive in culture and customs; uncivilized. 野蛮的，未开化的文化和习惯原始的; 不文明的
