At the section with non lithology key bed, the key bed could be selected according to the lithology combination and the particle variation.

在无岩性标志层的层段，则根据岩性组合及粒度变化选择标志层。

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Later in the paper, a correlation between the main coal-seams in this province is made, in combination with the traditional method of the key bed, coal petrography and palaeontology.

然后，结合传统的标志层法、煤岩学及古生物学方法，对该区主要煤层进行对比。

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I heard the key turn in the front door and I was out of bed like a shot.

我听见钥匙开前门的声音，立刻从床上起来了。

《柯林斯英汉双解大词典》

Education is key and with bed bugs you must understand their behavior to understand how to keep them away!

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"In coal bed technology, they kept at it until they found the key that unlocked the door and things started happening, which is likely the way methane hydrates will develop, " says Rose.

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