Explanation

Ultrasound is sound with frequencies greater than 20 kilohertz.

This frequency is the approximate upper audible limit of human hearing in healthy young adults

while 

The first article on the history of ultrasound was written in 1948

Explanation

Word Government Summit 2023

Venue: Dubai, UAE

Date: 13 February 2023

Theme 2023: Shaping Future Governments 

Explanation

Air Commodore Sir Frank Whittle, was an English Royal Air Force air officer. He is credited with inventing the turbojet engine. A patent was submitted by Maxime Guillaume in 1921 for a similar invention; however, this was technically unfeasible at the time.

RY30012023

Explanation

In late 1940, before the U.S. entered World War II and just after earning his doctorate, Drew was recruited by John Scudder to help set up and administer an early prototype program for blood storage and preservation

RY30012023

Explanation

Europe's largest deposit of rare earth metals discovered in Sweden in January 2023.

Explanation

Alexei Leonov was the first human being to walk in space,

the man who would have been first on the moon had the Soviets beaten the Americans.

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First man who travelled in Space was Yuri Gagarin in 1961

First man who Walk in Space was Alexei Leonov in 1965

First man who Walk on Moon was Neil Armstrong in 1969

Explanation

Johannes Kepler published his first two laws about planetary motion in 1609, having found them by analyzing the astronomical observations of Tycho Brahe.

Kepler's third law was published in 1619.

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RY 15-01-2023

Explanation

• Mother can feed the child for up to 2 years
• ***
• The American Academy of Pediatrics (AAP):
• Recommends breastfeeding exclusively for 6 months,
• then breastfeeding in addition to the start of solid foods for at least 2 years.
• After that breastfeeding can continue for as long as the mother and child wish.
  

Explanation

In 1928, at St. Mary's Hospital, London, Alexander Fleming discovered penicillin.

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ND30-12-2022

Explanation

 EMT RESCUE 1122 "CPR" related question":