Natural changed to the ecosystem relate to environmental shock that occur naturally. Natural changes include floods, volcanic activity, hurricanes, etc. They can be destructive, but they also have advantages. Floods have the contribution of nutrients to the soil which was lacking. It can also relocate fishes and organisms living in bodies of water which improves the ecosystem.
        
             
        
        
        
There are many different types of cancer, each caused by different factors is the statement which best explains why cancer is so difficult to cure.
The option D is correct.
Explanation:
Cancer is an abnormal growth of cells in which the check on the cell cycle and programmed cell death ceases.
The mutation in the genes or DNA causes cell to divide profusely overpowering the check points of the cell division.
The cancer in particular cell is no longer at a single cell but it metastasizes to other organs and building its own capillaries to get nutrition.It gets difficult to treat the disease as many organs get affected.
Cancer is caused by lifestyle, mutation, carcinogens, eating habits, genetic factors or age related etc.
There are different strategies required to treat and prevent the cancers caused by different factors. So not one factor can be taken for the treatment purpose. Different organs affected with cancer require different line of treatment so it gets difficult to apply same strategy for everyone.
 
        
             
        
        
        
Answer: Cell wall, DNA,  plasma membrane
Explanation:
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The major species at the points are:
- A =  acetic acid
- B = acetate ion
- C = acetate ion
- D = hydroxide ion
<h3>What are the the major species, other than water and potassium ions, at the given points?</h3>
The reaction between acetic acid and potassium hydroxide is a neutralization reaction.
The equation of the reaction is given below:
- CH₃COOH + KOH → CH₃COOK + H₂O
The graph of the titration shown, the major species at the points are as follows:
- A =  acetic acid
- B = acetate ion
- C = acetate ion
- D = hydroxide ion
In conclusion, the reaction between acetic acid and potassium hydroxide produces potassium acetate and water.
Learn more about acetate ion at: brainly.com/question/27140137
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