The image given is incomplete. The complete image is attached below.
Answer:
A. A Squirrel, robin, and field mouse
Explanation:
Food web is defined as the interconnection between different food chains which shows how organisms from different food chains are connected with each other for food in the ecological community.
In the attached image, there are three consumers which depend on the same producer for food. Those three consumer are squirrel, robin, and field mouse feeding over plant seeds (producer) for survival.
Hence, the correct option is A.
 
        
             
        
        
        
Answer:
<em><u>B</u></em>
Explanation:
cell is the first organization level 
tissue is the second level
organ is the third level
organ systam is the fourth level
organsim is the last organization level
 
        
             
        
        
        
Answer:
The correct answer is "Redwood tree; human being; Paramecium; White Blood Cell; Escherichia coli; Chickenpox virus; Ribosome; Prion fibril; Water molecule; Sulfur atom".
Explanation:
Redwood trees are gigantic trees, and its size can reach up to 90 meters.
The average size of a human being is 1.7 meters for males and 1.6 meters for females.
Paramecium are members of the protozoa genus, among the largest unicellular algae. Its average size is among 50 to 330 micrometers.
White Blood Cell are up to 17 micrometers in diameter.
Escherichia coli is a type of bacteria, as a prokaryotic organism is much more smaller than a eukaryotic cell such asa the white blood cell. Escherichia coli is up to 2 micrometers in diameter.
Chickenpox virus are among the largest viruses, they are from 150 to 200 nanometers in diameter.
Ribosomes vary on size depending if they are Prokaryotic or Eukaryotic, where the first are up to 20 nanometers and the second are up to 30 nanometers.
Prion fibrils are aggregates comprised of several protein units. It size varies depending on the number of proteins, but the ones containing around 200 units can reach up to 27 nanometers. 
Water molecule is comprised of two atoms of oxygen and one atom of hydrogen, its size is measured with picometers (1 picometer is equal to 1000 nanometers). A water molecule has a size of 275 picometers.
Sulfur atom is the smallest in the list. Its size is around 100 picometers.
 
        
             
        
        
        
I believe the answer is decomposers. Does that make sense in the context of what you have learned in class? If you look up "the circle of phosphorous," you can see images that show that decomposers, like fungi and microbes break down dead animals and plants using some of their phosphorous, but what isn't used is returned to the soil. The same can be said for sulfur. Decomposers like fungi and bacteria break down dead plants and animals and return sulfur to the soil. 
I want to warn you that there is a slight possibility that I might be incorrect. I am still pretty sure I am right. The only thing that makes me question the correctness of my answer is another brainily question I saw when i was looking up this stuff. Two people had responded to that Middle schoolers question and had said the answer was producers. They didn't give any explanation for their answers. So, I am confused as to how they both got the same answer that was different from mine.  No material that I have seen regarding either the phosphorous cycle or sulfur cycle has shown plants as RETURNING the most sulfur and phosphorous into the soil. Usually, it has been depicted that producers, such as plants, UTILIZE the most phosphorous and Sulfur from the soil.
        
             
        
        
        
Answer:
Permeability of plasma membrane is the rate of passive diffusion molecules across the biomembrane.