Passive transpoet is the movement of particulars across the membrane from area of what to an area of what

Passive transport is the movement of particulars across the membrane from area of high to an area of low concentration.

Explanation:

Passive transport is a transmembrane cellular transport mechanism characterized by the fact that it does not require energy.

What enables passive transport is the concentration gradient of a particle, which moves across the membrane from a site of high concentration to a site of low concentration.

Two known forms of passive transport are simple diffusion and facilitated diffusion.

the answer is d.) homologous; have mammary glands

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate