[With some straws, she is making a musical pipe.]

Question

1. When you blow across the top of "a)the straw", the air vibrates inside "b)the straw" and makes a sound.
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a)the straw b)the straw
Are they the specific straw or in generic use?

When "c)the straw" is shorter, the air loses less energy and vibrates faster.
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Does "c)the straw" mean the specific straw or is it in generic use?

Answer 1

Again, these uses of "the straw" are referring to a particular straw.