Fill in the blanks with the most appropriate option:-

Where ………you spend your last summer vacations?

did

The correct option to fill in the blanks is did.

The sentence is about asking someone where they spent their last summer vacation. The verb "spend" is in the past tense, singular form. The auxiliary verb "did" is used to form the past tense of the verb "spend" in the second person singular form. It is the most appropriate auxiliary verb to use in this context, as it describes the fact that the speaker is asking about an event that happened in the past.

The other options are not as appropriate:

• Do is the present tense, singular form of the verb "to do". It is not as appropriate as "did", as it does not convey the same sense of pastness or remoteness.
• Does is the present tense, singular form of the verb "to do". It is not as appropriate as "did", as it does not convey the same sense of pastness or remoteness.
• Done is the past participle of the verb "to do". It is not as appropriate as "did", as it is not used to form the past tense of the verb "spend".