下列各组中全部都属于自然资源的是（   ）

    Mark lived in a village far away. One day he became very ill and everyone thought he would 1 soon. They sent for a doctor. Two days 2 the doctor came and looked over the sick man.3 asked for a pen and some paper to write down the name of the medicine. But there was no pen 4 paper in the village, because no one could write.

    The doctor 5 up a piece of burnt wood from the fire and wrote the name of the medicine on the 6 of the house. “ Get this medicine for him, and he will get 7 soon. ” he said.  Mark's family and friends did not know8 to do. They could not read the strange words. Then a young man 9an idea. He took off the door of the house, put it on his carriage(马车) and drove to the nearest 10. He bought the medicine there, and Mark was soon well again.

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