6.Sea mammals must emerge periodically to breathe.
海生哺乳动物必须不断地浮现出海面呼吸
7.The boa feeds on birds and small mammals.
蟒主要吃鸟和小的哺乳动物。
8.several small gregarious cetacean mammals
几种小型群居的类哺乳动物
9.mammals have, by and large, bigger brains than reptiles.
总的说来，哺乳动物的脑比爬动物大。
10.There are lots of marine mammals such as whales and seals in the sea.
海洋里有许多诸如鱼和海豹类的海生哺乳动物。
11.Bats are the only mammals to have wings and to achieve sustained flight.
蝙蝠唯一的有翅膀且能持的哺乳动物。
12.the insulation of marine mammals in temperate seas pre-adapts them for polar seas.
把海洋哺乳类动物隔离在温带海域中使其预适应极地海域。
13.order Chiroptera) of the only mammals to have evolved true flight.
九百多种,属翼手目。唯一一类演化出真正翔能力的哺乳动物的统称。
14.massive plantigrade carnivorous or omnivorous mammals with long shaggy coats and strong claws.
结实的食肉或杂食性跖哺乳动物，皮毛长而粗糙，爪有力。
15.any of various fissiped mammals with nonretractile claws and typically long muzzles.
爪不能伸缩、长鼻子的多种裂足哺乳动物。
16.any of several small ungulate mammals of Africa and Asia with rodent-like incisors and feet with hooflike toes.
非洲和亚洲的有爪类哺乳动物，有类似啮齿动物的门牙和类似有蹄动物的脚。
17.Forests are important habitats for birds and, in temperate forests, small mammals which inhabit the dense understorey.
森林对鸟类来说重要的栖息地，而且在温带森林里，小型的哺乳动物居住在稠密的森林下层。
18.any of various undomesticated mammals of the family Canidae that are thought to resemble domestic dogs as distinguished from jackals or wolves.
犬科动物中各种非家的哺乳动物，由于区别于豺和狼而被认为象狗。
19.Schistosome infected people or other mammals from the discharge of faecal egg, if manure contaminated the water, eggs were brought into the water, hatched miracidium in the water.
感染血吸虫的人或其它哺乳动物从粪便中排出虫卵，若粪便污染了水，虫卵被带进水中，在水里孵出毛蚴。
20.Any of several very large,extinct proboscidian mammals of the genus Mammut(sometimes Mastodon,resembling the elephant but having molar teeth of a different structure.
为了取奶。
动物大。
