Question

It is difficult to estimate _______ water flow

Answer 1

Answer:

It is difficult to estimate the water flow

Explanation:

Answer - The

Answer 2

Answer:

It is difficult to estimate _______ water flow

The answer is the

the (before a singular or plural noun)

The word "the" is one of the most common words in English. It is our only definite article. Nouns in English are preceded by the definite article when the speaker believes that the listener already knows what he is referring to.