This is less than the total biological production in the main water column, or pelagic zone.
它比主水体或远洋区的生物总产量要少一些。
This is less than the total biological production in the main water column, or pelagic zone, which scientists believe to be between around 0.6 and 1.8 gigatonnes of carbon per year.
它比主水体或深海区动物产物——科学家们认为，其总数在每年约6千万到1亿8千万吨碳——的总数要少。
A coal mining method with a combination of a slicing and caving, a double benefit in control of water conducted crack zone development and in reduction of coal production cost can be obtained.
对厚煤层采用分层与放顶煤相结合的采煤方法，既可控制导水裂缝带的发育高度，又可降低生产成本。
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