This question requires a clear understanding of two commonly confused words that sound similar but have distinct meanings: "complemented" and "complimented". Choosing the correct word for each blank depends entirely on the context and the intended meaning within the sentence.

Words: Complemented and Complimented Defined

Let's precisely define these two words to understand their appropriate usage:

• Complemented: This word is the past tense of the verb "complement." To "complement" means to complete, enhance, or add to something in a way that improves or perfects it. When one thing complements another, they go well together or make each other better.
• Complimented: This word is the past tense of the verb "compliment." To "compliment" means to express praise, admiration, or a polite remark to someone. It is about giving positive feedback or commendation.

Blanks: Analyzing the Sentence Structure

Now, let's apply these definitions to fill in the blanks in the given sentence: "The dress _________ her so well that they all immediately _________ her on her appearance."

First Blank: Dress and Appearance Relationship

• The first part of the sentence, "The dress _________ her so well," describes the effect the dress had on the person.
• If the dress fit "so well," it means it made her look better or enhanced her appearance.
• The word that means to enhance, complete, or make something better is "complemented." The dress added positively to her overall look.
• Therefore, "complemented" is the appropriate word for the first blank.

Second Blank: Expressing Praise

• The second part of the sentence, "they all immediately _________ her on her appearance," describes the action taken by others regarding her look.
• When people react to someone's appearance by saying it's good or expressing admiration, they are giving praise.
• The word that means to express praise or admiration is "complimented."
• Therefore, "complimented" is the correct word for the second blank.

Option: Selecting the Best Fit

Based on our detailed analysis, the first blank requires "complemented", and the second blank requires "complimented". This specific pair accurately completes the sentence, conveying that the dress enhanced her look, prompting others to praise her appearance.