Answer/Explanation:
Cells of a similar type are organized together to make tissues. Different types of tisues come together to perform a similar function as part of organs.
For example, take the organ the stomach. There are various tissues that make up the stomach, including, for example, mucosa, and muscle tissue.
The mucosa tissue of the stomach is made up of secretory cells such as parietal cells, which secrete hydrochloric acid, and foveolar cells which produce mucus that protects the lining of the stomach.
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.
Answer:
B. interconnected
Explanation:
All the systems in our bodies (humans are indeed animals) are connected with each other to create a functional being. The blood flows throughout the body, providing nutrients; the bones support the structure and protect the heart and lungs. They work together.
Why not A: The systems are all completely necessary. There's nothing extraneous in our bodies, because extraneous stuff takes up energy, and our biology is incredibly economical.
Why not B: They're not interchangeable. How would you like your bones to turn to blood? Uh-huh.
Why not D: They interact with each other consistently, so they're not separate or segregated.