CONCEITED = excessively proud of oneself; vain.

smug = too pleased with yourself

modest = not talking too much about your own abilities

diffident = not having confidence in your own strengths

shy = nervous or timid in the company of other people.

Hence option ‘A’ is the correct answer.

DESPISE = to hate somebody very much

admire – regard with respect or warm approval.

approve – officially agree to or accept as satisfactory

abhor – to hate something very much

appreciate – to understand a problem

Hence, the option ‘C’ is the correct answer.

Squalid: (of a place) extremely dirty and unpleasant, especially as a result of poverty or neglect.

Filthy: disgustingly dirty.

Violent: using or involving physical force intended to hurt, damage, or kill someone or something.

Clean: free from dirt, marks, or stains.

Infested: (of insects or animals) be present (in a place or site) in large numbers, typically so as to cause damage or disease.

Hence, option C is the correct answer.

Expandable: able to be made larger or more extensive.

Flexible: capable of bending easily without breaking.

Resistant: offering resistance to something or someone.
Rigid: unable to bend or be forced out of shape; not flexible.

Straight: extending or moving uniformly in one direction only; without a curve or bend.

Hence, option A is the correct answer.

Submissive: ready to conform to the authority or will of others; meekly obedient or passive.

Miserly: of or characteristic of a miser.

Dutiful: conscientiously or obediently fulfilling one's duty.

Obedient: complying or willing to comply with an order or request; submissive to another's authority.

Stubborn: having or showing dogged determination not to change one's attitude or position on something, especially in spite of good arguments or reasons to do so.

Hence, option D is the correct answer.

Brisk: active and energetic.

Slow: moving or operating, or designed to do so, only at a low speed; not quick or fast.

Expert: having or involving a great deal of knowledge or skill in a particular area.

Smart: (of a person) clean, tidy, and well dressed.

Rapid: happening in a short time or at a great rate.

Hence, option A is the correct answer.

Eminent: (of a person) famous and respected within a particular sphere.

Prominent: important; famous.

Efficient: (of a system or machine) achieving maximum productivity with minimum wasted effort or expense.

Unknown: not known or familiar.

Pleasant: giving a sense of happy satisfaction or enjoyment.

Hence, option A is the correct answer.

Commence: begin.

Try: make an attempt or effort to do something.

Collect: bring or gather together (a number of things).

Praise: express warm approval or admiration of.

Start: begin or be reckoned from a particular point in time or space; come into being.

Hence, option D is the correct answer.

Assert: state a fact or belief confidently and forcefully.

Refute: prove (a statement or theory) to be wrong or false; disprove.

Enter: come or go into (a place).

Specify: identify clearly and definitely.

Emphasize: give special importance or value to (something) in speaking or writing.

Hence, option D is the correct answer.

Let us learn the meaning of the all the words:

Strange (adjective): not previously visited, seen, or encountered; unfamiliar or alien.

Durable (adjective): able to withstand wear, pressure, or damage; hard-wearing.

Delicate (adjective): easily broken or damaged or fragile.

Unknown (adjective): not known or unrevealed.

Familiar (adjective): well-known from long or close association.

Thus, it can be clearly deduced that ‘familiar’ is the best choice as the antonym of ‘Strange’.

Hence, option D is the correct answer.