| 1 | A method of making a design by placing a piece of paper on top of an object and then rubbing over it, as with a pencil or charcoal. | |
| 2 | First we introduce north Korea's energy distribution: north Korea's energy structure with coal primarily. | |
| 3 | The biota of Upper Carboniferous is dominated by fusulinid and secondly by brachiopod and coral with flourished fossil plants in the lower pail. | |
| 4 | Below Carboniferous-Permian coal-bearing formations in coal fields of North China, there is a stratum of Ordovician limestone containing an abundant supply of water. | |
| 5 | The correlation of oil-source rock indicated that there are three sets of source rock, namely Cambrian-Ordovician, Carboniferous-Permian and Jurassic system. |
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