Which statement is true about the speed of light?

A) Light travels relatively slowly.

B) Distance in space is measured using the speed of light,

C)Time in space is measured using the speed of light,

D) The speed of light is unknown.

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems

What are the characteristics of subsystem

Where are chlorophyll molecules located within the chloroplasts?