In the sentence 'It's not ____ cheap, but high quality too.', which word completes it?

• A. only
• B. very
• C. quite
• D. so

Answer: (A)

Not only is a fixed structure used to emphasize two positive qualities together. In this sentence you want to say something isn’t just cheap; it’s also high quality. The natural way to express that is by using not only followed by cheap, with the second quality introduced by but and reinforced by too. The word that fits the blank is only, because it completes the standard not only cheap, but high quality too construction. Using very, quite, or so would change the meaning or sound odd in this context and wouldn’t link the two qualities as effectively.