She found ___ interesting book at the library.

The correct answer is "an" because the word "interesting" starts with a vowel sound, which requires the use of "an" as the indefinite article.

Have you seen ___ movie "Titanic"?

The correct answer is "the" because "Titanic" is a specific movie title, and specific nouns require the definite article "the".

He wants to buy ___ new car.

The correct answer is "a" because "new car" is a non-specific item, and "car" starts with a consonant sound.

I need ___ umbrella because it's raining.

The correct answer is "an" because "umbrella" starts with a vowel sound.

They live in ___ apartment downtown.

The correct answer is "an" because "apartment" starts with a vowel sound.

He is ___ only child in the family.

The correct answer is "the" because "only child" is a specific description that requires the definite article "the".

She wore ___ blue dress to the party.

The correct answer is "a" because "blue dress" is a non-specific item, and "dress" starts with a consonant sound.

___ Earth orbits around ___ Sun.

The correct answer is "the / the" because both "Earth" and "Sun" are specific nouns that require the definite article "the".

He's reading ___ book you recommended.

The correct answer is "the" because it refers to a specific book that was recommended.

I saw ___ elephant at ___ zoo yesterday.

The correct answer is "an / the" because "elephant" starts with a vowel sound and "zoo" is a specific place that requires the definite article "the".

There's ___ interesting article in ___ newspaper today.

The correct answer is "an / the" because "interesting" starts with a vowel sound and "newspaper" is a specific item that requires the definite article "the".

She wants to visit ___ United States next year.

The correct answer is "the" because "United States" is a specific country name that requires the definite article "the".

He is ___ good friend of mine.

The correct answer is "a" because "good friend" is a non-specific description that starts with a consonant sound.

She wants to learn ___ piano.

The correct answer is "the" because "piano" refers to a specific instrument in this context.

Have you seen ___ Eiffel Tower?

The correct answer is "the" because "Eiffel Tower" is a specific landmark that requires the definite article "the".

___ cat is sleeping on ___ sofa.

The correct answer is "the / the" because both "cat" and "sofa" are specific items in this context that require the definite article "the".

There is ___ beautiful garden behind ___ house.

The correct answer is "a / the" because "beautiful garden" is a non-specific description and "house" is a specific item that requires the definite article "the".

___ government has announced ___ new policy.

The correct answer is "the / a" because "government" is a specific entity and "new policy" is a non-specific description.

Have you read ___ book by ___ Hemingway?

The correct answer is "a / the" because "book" is a non-specific item and "Hemingway" is a specific author that requires the definite article "the".

___ sun sets in ___ west.

The correct answer is "the / the" because both "sun" and "west" are specific nouns that require the definite article "the".