Title: Solar energy.
Question: In 2002, the Sun provided more energy in one hour than humans used in what span of time?

Title: Energy.
Question: What are remarkably inefficient in their use of the energy they receive?

Title: Mandolin.
Question: What type of mandolin do rock musicians today use?

Title: High-definition television.
Question:
What aspect ratio was agreed upon due to the influence of widescreen cinema?