Answer:
<u>Correct parallel structure:</u> Some workplaces require wearing personal protective equipment such as gloves, goggles, earplugs, and a helmet.
<u>Faulty parallel structure:</u> Studies show that enforcing a dress code increases productivity, strengthens unity, and is helping to establish the company brand.
<u>Correct parallel structure:</u> Some employees must wear uniforms, such as those who work at security agencies, restaurants, and department stores.
<u>Correct parallel structure:</u> Other studies show that not having a dress code at the workplace encourages self-expression, creativity, originality, and innovation.
Explanation:
Parallelism refers to the use of the same grammatical constructions. In that respect, sentences one, three and four contain similar lists of nouns separated by commas. On the other hand, the second sentence includes a list of two actions in the Present Simple, while the last one is in the Present Continuous. Thus, the correct version of the sentence is the following:
<em>Studies show that enforcing a dress code </em><em>increases </em><em>productivity, </em><em>strengthens </em><em>unity, and </em><em>helps </em><em>to establish the company brand.</em>
