Question

which detail shows that kamens light - controlled systems were very good?
kamen was introduced to a man who sold audio - visual equipment for big light and music shows.
when he was sixteen, kamen spent all summer building high - powered light - controlled systems.
one of his inventions was used in theaters, the museum of natural history, and the new york planetarium.
to make one of his devices, he bought every kind of electrical equipment that he could find.

Explanation:

To determine which detail shows Kamen's light - controlled systems were good, we analyze each option.

• The first option just mentions an introduction to a person selling audio - visual equipment. It doesn't directly show the quality of Kamen's systems.
• The second option tells about Kamen spending time building systems. But spending time doesn't necessarily mean the systems are good.
• The third option states that one of his inventions was used in theaters, the Museum of Natural History, and the New York Planetarium. If it was used in such important and diverse places, it implies the system was good.
• The fourth option is about buying electrical equipment. Buying equipment is a part of the process but doesn't show the quality of the final system.

Answer:

One of his inventions was used in theaters, the Museum of Natural History, and the New York Planetarium.