Which statement is true regarding speed, velocity, and acceleration?
A. Velocity is speed in a certain direction; acceleration is a change in velocity.
B. Acceleration is speed in a certain direction; velocity is a change in acceleration.
C. Velocity is a change in speed; acceleration is a change in direction.

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.