Modal Auxiliary: 'Has to'

Explanation:
- Modal auxiliaries are a type of auxiliary verb that are used to express certain meanings such as possibility, necessity, obligation, ability, etc. in a sentence.
- In this given sentence, we need to choose the correct modal auxiliary to express the idea of obligation or necessity.

Options:
a) Has to - This modal auxiliary is used to express a requirement or obligation. It indicates that something is necessary or must happen.
b) Have to - This modal auxiliary is also used to express a requirement or obligation, but it is used for plural subjects such as 'they', 'we', 'you', etc.
c) Had to - This modal auxiliary is used to express a past obligation or necessity. It indicates that something was necessary or had to happen in the past.
d) Shall - This modal auxiliary is used to express a future action or intention. It is often used in formal or legal contexts.

Correct Answer:
The correct modal auxiliary to fill in the blank is 'Has to' (option A).

Explanation:
- The sentence states that "Everyone _____ be present tomorrow since it is the Independence Day."
- Here, the word 'everyone' is a singular pronoun that refers to every person or all people.
- Since 'everyone' is a singular subject, we need to use the singular form of the modal auxiliary.
- The correct phrase should be "Everyone has to be present tomorrow since it is the Independence Day."
- This conveys the idea that it is necessary or obligatory for every person to be present on Independence Day.

Example Usage:
- Everyone has to attend the meeting tomorrow.
- She has to finish her homework before going out to play.
- They have to wear uniforms to school.

Additional Information:
- Modal auxiliaries are always followed by the base form of the main verb (infinitive without 'to').

A