Most information was collected by direct observation of the animals' behaviour.

大部分信息都是通过直接观察动物的行为收集到的。

《牛津词典》

FINDING SOME: First Direct Observation of Dark matter.

正在发现一些：对于黑洞的最早的直接观测结果。

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The historical nature of macroevolutionary study involves inferencefrom fossils and DNA rather than direct observation.

宏观进化论研究具有史学性质，它的质料来自化石和DNA，而不是直接观察。

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Dark matter remains a mystery because there has been no direct observation of it, he explained.

CNN: Space station detector gives first clues to 'dark matter'

This is a transition from speculation about the size of streambed material to direct observation of it.

FORBES: Curiosity Finds Evidence Of Ancient Stream On Mars

Of course, it is thanks to Planck that we now know there is slightly more "stuff" out there than we thought, even if most of it is in a form beyond direct observation.

BBC: Planck telescope: A map of all the 'stuff' in the cosmos