GMAT Sentence Correction (SC) | A group of industrial designers suggested that the use of bamboo

The two elements of comparison are:

X: Bamboo is versatile
Y: Wood is versatile

It is generally accepted to omit the repeated parts in the second element, but retaining the same does not make the sentence wrong.

Bamboo is as versatile a material as wood (is).... omitting "is" is acceptable, but retaining "is" is correct a swell. Therefore
...

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