Asolid substance turns into a liquid. which best describes this change?

All cells are made of four types of acids, lipids, proteins, and carbohydrates.

What are the major types of a chemical compound

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!