Select the most appropriate option to substitute the underlined segment in the given sentence. If there is no need to substitute it, select ‘No substitution required’.

Corona virus has not yet reached some parts in world.

The correct answer is- 'some parts of the world.'
Key Points

• We know that a definite is used when we talk about a specific thing.
• In the given sentence, we are talking about a specific world, that is the world in which we humans live.
• So we should use a definite article (the) before the word 'world.'
• And the preposition 'of' expresses the relationship of a part of something to its whole.
  • Example: Some parts of his body were injured.
• Thus option 3 is the correct answer.

• Both a definite or an indefinite article can be used with the word 'world,' it depends on which context it has been used.
  • If you are talking about a specific world, then u would use the world.
    • Example: If Humans don’t act quickly, the world will be irreparably damaged.
  • If you are talking about a place that is not specific or imaginary, then use a world.
    • Example: We could live in a perfect world if we all exhibited a love for each other.