Explanation

Email addresses cannot contain spaces, as they are not valid characters in email formatting.

Other characters like underscore (_) and at sign (@) are allowed. T

The at sign (@) is essential because it separates the username from the domain in an email address.

Explanation

Abu Bakr  was a sahabi, one of the companions of Muhammad and the first Caliph of Islam.

He was also Muhammad's father-in-law through Aisha.

His real name was Abdullah or Abul-Kaaba and Abu Bakr was his kunya.

Explanation

The menu bar is the part of a browser or application window, typically at the top left side, that houses drop-down menus that allow the user to interact with the content or application in various ways.

Explanation

The Zulfiqar was one of the 7^th or 9^th swords of the Prophet.

He came into its possession either by taking it from a conquered enemy at the battle of Badr.