I believe the universe is 13.8 billion years old. Possibly longer, or possibly shorter. Correct me if I'm wrong.
D: it’s typically associated with cloudy weather and precipitation.
Answer:D
Explanation: Because it has the least amount of density in it. All the others are heavier, meaning they will sink. Just like if you drop a rock water and a feather, the feather will float.
Density def:
Density, mass of a unit volume of a material substance. ... Density offers a convenient means of obtaining the mass of a body from its volume or vice versa; the mass is equal to the volume multiplied by the density (M = Vd), while the volume is equal to the mass divided by the density (V = M/d).
its the circulatory system
