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.

[Q]: 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.
[A]: a certain number of yarns


[Q]: This should be secured in the stern-sheets of the first boat.
[A]: This


[Q]: Manila hawser-laid rope is supplied to the Royal Navy in coils of 120 fathoms, and it is marked with one red rogue's yarn in each of two strands.
[A]:
Manila hawser-laid rope