question: Answer this question.

A UNESCO heritage site, the major Peruvian tourist attraction Machu Picchu was built by what pre-Columbian civilization?
answer: incans
question: Answer this question.

Harald ___ Gromson was the king of Denmark in the 10th century and is regarded as having united Denmark, Norway, and Sweden. How is his name popular in the technological world?
answer: bluetooth
question: Answer this question.

In motion-detection and automated lighting sensors what does PIR mean?
answer:
passive infrared