Select the most appropriate word to fill in the blank.

You have to do _____ intensive training to become a nurse.

an

The most appropriate word to fill in the blank is:

☀ an

The sentence would read: "You have to do an intensive training to become a nurse."

Explanation: "An" is used before words that start with a vowel sound, and "intensive" starts with a vowel sound ("i"). The other options don't fit the context:

• The: This is used when we are referring to a specific noun that both the speaker and listener know.

• A: This is used before words that start with a consonant sound, not a vowel sound.

• One: This isn't necessary in this context and doesn't fit the sentence structure.