In this task, you are given a sentence. You must find the primary subject in the supplied sentence. The output must be a sub-sequence in the sentence.
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Question: Direction of the lay and description.

Answer: the lay

Question: Next, a certain number of yarns are twisted together to form strands which, at the Admiralty Ropery, Chatham, are usually 150 fathoms in length when completed.

Answer: a certain number of yarns

Question: When mature the abaca plant, which grows to a height of from 10 to 30 ft, is felled and the fibre from the leaf sheaths is stripped off.

Answer:
the abaca plant