For centuries, scientists believed that light waves traveled through a substance called "aether." Which of the following facts refutes this belief? A.
Light waves can propagate through a vacuum.
B.
Aether has never been observed.
C.
Light waves can have many different wavelengths and frequencies.
D.
Light waves can travel extremely long distances.

When elements that form a mineral dissolve in hot water, they form a mixture called a(n) a)geode b)vein c)evaporation d)crystallization e)magma f)lava g)solution h)gem

What's the waste product of electrons and pyruvate combining in fermentation?  

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.