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This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

As in the other Western Romance languages, the main plural expression is the suffix -s, which may create morphological alternations similar to the ones found in gender inflection, albeit more rarely. The most important one is the addition of -o- before certain consonant groups, a phonetic phenomenon that does not affect feminine forms: el pols/els polsos ("the pulse"/"the pulses") vs. la pols/les pols ("the dust"/"the dusts").
Output:
What is the usual way to make a plural?