However, scientists believe they were not the first animals on Earth.

然而，科学家们相信他们不是地球上第一种动物。

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The beetles are the first animals found to have a screw-and-nut mechanism in their bodies.

人们也是第一次在这种甲虫身上看到动物有螺丝——螺母式的身体构造。

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Scientists believe that creatures on the island were cut off after a land bridge disappeared or that the first animals arrived there on a form of natural rafts that were blown out to sea.

科学家们相信，岛上的生物在大陆桥消失之后与世隔绝，或者第一批到来的动物是攀爬过被大风吹倒的大树，然后漂流到岛上的。

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But first,we tell about a new organization that is finding homes for animals and helping American soldiers at the same time.

VOA: special.2009.12.11

It has other terms that give commandments about the observance of the festivals, various festivals, the dedication of first fruits to God, the dedication of first born animals to God and so on; things that were not in the Exodus 20 Decalogue.

它还给出了其它的条款，包括各种节日庆祝仪式的戒律,规定将初熟之物和头生的牲畜供奉给上帝等，这些条例在,《出埃及记》第20章里都没有出现。

耶鲁公开课 - 旧约导论课程节选

The group says this is the first and only teaching hospital for animals to operate within an aquarium.

VOA: special.2009.09.18

The researchers then trained a new group of rats to discriminate between the odours the first animals could not tell apart by rewarding them over and over with sips water for choosing the appropriate hole.

BBC: Sense of smell 'can be improved through training'

It's not the first time animals have reached the skies ahead of humans.

CNN: Reports: Monkey soars from Iran into space -- and back

The first is that animals in the middle have more neighbours than those at the edges, and this greater number reduces the chance of a particular individual being selected by a predator.

ECONOMIST: Animal behaviour