Explanation

• Polio Vaccines: Developed to prevent poliomyelitis, a viral disease causing paralysis.
• Jonas Salk (US, 1950s): Created the first inactivated (killed) polio vaccine; tested on himself and family in 1953; officially used in 1955.
• Albert Sabin (1961): Developed the live attenuated (weakened) oral polio vaccine.
• Recent Campaigns: Israel launched a polio vaccine drive in April 2022 after 1988 efforts.

Last verified on 03-04-2026

Explanation

Vasco da Gama was a famous explorer and navigator from Portugal.

Additional information:

• Born: 1460, Sines, Portugal
• Died: 1524, Cochin, India
• Famous Achievement: First European to reach India by sea in 1498
• Significance: Opened direct maritime trade between Europe and Asia

Last verified on 15-01-2026

Explanation

• Isaac Newton (1642–1727) was an English physicist and mathematician.
• He formulated the laws of motion and law of universal gravitation.
• His work laid the foundation for classical mechanics.

Last verified on 02-04-2026

Explanation

• Microsoft was founded on April 4, 1975.
• It was founded by Bill Gates and Paul. Allen in Albuquerque, New Mexico.

Last verified on 02-03-2026

Explanation

• Alexander Graham Bell is credited as the inventor of the telephone.
• He was awarded the first successful patent for it.
• The telephone was invented in 1876.
• Bell made the first-ever telephone call to his assistant Thomas Watson.

Last verified on 31-03-2026