“The dress _________ her so well that they all immediately _________ her on her appearance.

The words that best fill the blanks in the above sentence are

The correct option is complemented, complimented.

To determine the correct words to fill the blanks, we need to understand the distinct meanings of the homophones complement and compliment:
1. Complement (verb): This means to contribute extra features to someone or something in a way that improves or emphasizes their qualities, or to go well with something else. In the context of the sentence, "The dress complemented her so well" means the dress went well with her or enhanced her appearance.
2. Compliment (verb): This means to politely congratulate or praise someone for something. In the context of the sentence, "they all immediately complimented her on her appearance" means they praised or expressed admiration for how she looked.

Therefore, the first blank requires complemented (to enhance/suit) and the second blank requires complimented (to praise), making "complemented, complimented" the correct pair.