Speech on inventors and inventions

Interntors present an interesting kind of people who think in peculiar ways sometimes. This ability allows them to view certain situations in ways in which other people cannot. Because of this, they can think of new ways of how such situations can be tackled. This is how inventions are born. A person with an inventive mind sees a new situation where he thinks of a new solution how he could improve this situation with his invention.

This process is continued continuously with new generations of inventors seeing and coming back to old situations over and over again, inventing new things along the way. 

The correct answer to go in the blank would be a) complement.

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