Ever ____ the invention of the hydrogen bomb, attempts have been made to harness the power of nuclear fusion for peaceful purposes.

The carbon dioxide gas given ____ by the fermenting vat was known as "fixed air".

The invention of printing on paper provided a technology ____ which information could be stored over the long term.

The key ____ inventive success often requires being in the right place at the right time.

An invention developed ____ one purpose will sometimes find use in entirely different circumstances.

Mark the letter A, B, C, or D to indicate the correct answer

In 1886 in the United States, a pharmacist named Dr. John Pemberton tried to invent a medicine because he wanted a cure for ____.

Throughout History Inventions ____ the world and the lives of people many times through history.

Ever since the first prehistoric stone tools, ____ have lived in a world shaped by invention.