Given the task definition, example input & output, solve the new input case.
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.
Example: Rope and its Usage
Output: Rope
The word 'Rope' is the key subject here, while Usage is a property of Rope.

New input case for you: The ropes supplied to the Royal Navy are made from various kinds of vegetable fibre which may differ in strength, weight, flexibility, hardness or resistance to wear, elasticity, resistance to weather, or behaviour when wet.
Output:
The ropes