The answer is brain and spinal cord
Answer:
it is greater than that of crust because e density increases as you go down
Answer: The correct answer is black because the product of its side and mass is lower.
Explanation: Density of a substance is defined as the mount of matter that can be stored in a given volume.
Mathematically,

As, density is inversely proportional to the volume of the substance.
The substance will be more denser if it has less volume and it will be less denser if the volume is more.
We are given two cubes having different sides.
Volume of the cube is calculated by using the formula:

where, a = side of the cube.
Black: The side of this cube is 2 and volume will be =
Yellow: The side of this cube is 3 and volume will be =
As, the volume of black cube is less. So, this cube will be more denser.
Density of black cube: 
Density of Yellow Cube: 
Hence, black cube will be more denser because the product of its side and mass is lower.
Explanation:
in dim light the iris contract ,the the pupils widens to allow more light to enter the eye,in bright light the iris relaxes and size of pupil becomes smaller to reduce amount of light entering the eye. NOTE: the muscle do not expand they either contract and relaxes
Breathing in air pollutants can irritate your airways. It may cause shortness of breath, coughing, wheezing, asthma episodes and chest pain. Overtime, exposure to air pollution puts you at risk for lung cancer, heart attack/strokes, etc. Some people are more at risks from others though