Explanation

"Old" starts with a vowel sound, so we use "an" before it.

Correct sentence: "Is your mother working in an old office building?"

Explanation

"The" is used for something specific already known to the speaker and listener.

Since the USB drive was already mentioned ("I lent you last week"), "the" is correct.

Explanation

• Prophet Musa (AS) is mentioned the most in the Quran.
• The name of Musa is mentioned 136 times in the Quran.

Explanation

The insoluble parts of cytoplasm are mainly the organelles, which include structures like the nucleus, mitochondria, ER, etc.

Mitochondria is a type of organelle, so the broader correct term is organelles.

Explanation

Micro molecules (or small molecules) have low molecular weight, like glucose or amino acids.

Macromolecules are large molecules like proteins, carbohydrates, and nucleic acids.

Explanation

"Who" is used as a relative pronoun for people in subject position.

Correct sentence: "I have met most of the people who are eager to take part in the competition."

Explanation

The era from 600 A.D to 1600 A.D is known as the period of Alchemists in Muslim history, especially in the Islamic Golden Age.

During this time, Muslim scholars like Jabir bin Hayyan advanced early chemical and alchemical knowledge.

Explanation

This is a well-known proverb: "A rolling stone gathers no moss."

It means a person who keeps moving or changing jobs doesn't gain responsibilities or stability.

Explanation

"Where" is used to refer to places in relative clauses.

Correct sentence: "Do you remember the town where you were born?"

Explanation

Pheretima posthuma is the common species of earthworm found in South Asia.

It belongs to the phylum Annelida.

It is important for soil fertility.