Explanation

The phrase "When I met him" is in the past tense, so we need a past continuous verb to show an action in progress at that time.

"Was going" correctly shows he was in the process of going to college when the meeting happened.

Explanation

Sarcina is a bacterial arrangement formed when cocci divide in three perpendicular planes, resulting in a cubical packet of 8 cells.

It is commonly seen in some Gram-positive cocci like Sarcina ventriculi.

Explanation

"He is vain of his beauty."

The correct preposition to use with "vain" (meaning overly proud) is "of."

"Vain of" means proud of (in a conceited way).

Explanation

 Those substances through which electric current cannot pass are called insulators.

Insulators have very high electrical resistance

. For example, wood, rubber, glass, paper, plastic and wax are insulators of electricity.

Insulators cannot conduct electricity due to absence of free electrons in them.

Explanation

AMPLE کافی

PLENTY OF کافی

Explanation

Explanation

The aperture refers to the diameter of the lens through which light enters.

It controls the amount of light reaching the lens, affecting brightness and focus.

Explanation

ATTAINMENI "حصول" یا "کامیابی"

ACHIEVEMENT کامیابی

Explanation

ACCOMPLISHMENT تکمیل

Achievement کامیابی

Explanation

Sonar stands for "Sound Navigation and Ranging."

It uses high-frequency sound waves (ultrasonic waves) to detect and locate objects underwater