Fill in the blanks with suitable articles:
____________ Statue of Liberty is at entrance to _____________ New York harbour.
a) The; the
b) A; a
c) No article; no article
d) The; no article

Hint: The English language has two articles: ‘the’ and ‘a/ an’. The definite article ‘the’ is used to refer to specific or particular nouns and the indefinite article ‘a/ an’ is used to modify non-specific or non-particular nouns.

Complete answer:
 An article is like an adjective and like adjectives, articles modify the noun. The English language has two articles: ‘the’ and ‘a/ an’. The definite article ‘the’ is used to refer to specific or particular nouns and the indefinite article ‘a/ an’ is used to modify non-specific or non-particular nouns.
To understand the above-given explanation consider – Definite article ‘the’ is used when we refer to something in particular, the indefinite article ‘a’ is used to refer to something in general and when the word begins in a consonant, and the indefinite article ‘an’ is used when the word begins in a vowel.
Now, in the above-given sentence, we are talking about two things, namely – Statue of Liberty and New York harbor. In this case, Statue of liberty refers to a particular monument thus we will use ‘the’, i.e. the definite article. And since New York harbor is a general place and a proper noun we will use no articles before it. So if we look at the options –
Only option (d) provides this combination as –
a) The; the – not correct
b) A; a – not correct
c) No article; no article – not correct
d) The; no article – correct
Thus option (d) is correct as per the above-given explanation.

Note:
 We use ‘no article’ when we refer to general ideas, plurals, or uncountable nouns, towns, cities, states, countries, lakes, single islands, continents, mountains, or with a proper noun unless the noun contains a prepositional phrase.