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]: Four-stranded (rot-proofed manila or sisal) rope, laid up round a heart or centre made of the same material, is known as shroud-laid rope.
[A]: Four-stranded (rot-proofed manila or sisal) rope


[Q]: Though it is not necessary to go deeply into the process of ropemaking, an elementary knowledge of its principles is desirable.
[A]: the process of ropemaking


[Q]: It should therefore be examined frequently for signs of deterioration.
[A]:
It