Explanation

The three countries that have not signed the CTBT are:

• India
• North Korea
• Pakistan

These countries are also among the eight Annex 2 states that have not ratified the treaty.

 The United States was the first nation to sign the treaty.

Signatories:187

Ratifiers: 178

Additional information 

CTBT stands for Comprehensive Nuclear-Test-Ban Treaty 

It's a multilateral treaty to ban nuclear weapons test explosions for both civilian and military purposes

Signed: 24 September 1996

Languages (6)

1. Arabic
2. Chinese
3. English
4. French
5. Russian
6. Spanish

Explanation

Michael Phelps has won the most Olympic medals in history.

He has won a total of 28 medals, 23 of which are gold, making him the most decorated Olympian of all time.

Phelps is an American former competitive swimmer.

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Explanation

The Treaty of Westphalia, signed in 1648, marked the end of two major conflicts:

The Thirty Years' War (1618–1648) in the Holy Roman Empire, involved various European powers, including Germany.

The Eighty Years' War (1568–1648) between Spain and the Dutch Republic, resulted in Dutch independence from Spanish rule.

Explanation

In Iran, the Karez system is locally known as Qanat (قنات).

It is an ancient underground irrigation system that taps into groundwater and channels it to the surface through gently sloping tunnels.

Explanation

The deepest trench in the Atlantic Ocean is the Puerto Rico Trench.

Its deepest point, known as the Milwaukee Deep.

It is reaches a depth of 8,376 meters (27,480 feet). 

Explanation

The League of Nations was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace.

Founded: 10 January 1920

Founder: Woodrow Wilson

Headquarters: Geneva, Switzerland

Ceased operations: April 20, 1946

Explanation

The Blue Mosque, also known as the Mosque of Sultan Ahmed.

It is one of the most famous landmarks in Istanbul, Turkey.

It was built in the early 17th century during the Ottoman Empire.

It is known for its stunning blue tiles and six minarets.

The mosque was commissioned by Sultan Ahmed I.

It took seven years to complete (1609-1616).

Explanation

A standard 400-meter oval track usually has 8 lanes in most professional and Olympic-level competitions.

Each lane is about 1.22 meters wide, ensuring fair distance for all runners.

Explanation

Nehru was a principal leader of the Indian nationalist movement in the 1930s and 1940s. 

Born: November 14, 1889, Prayagraj, India

Died: May 27, 1964, New Delhi, India

Explanation

Hassan al-Banna was assassinated on February 12, 1949, in Cairo, Egypt.

He was shot by unidentified assailants (widely believed to be state-sponsored due to his opposition to the Egyptian government).