The correct answer is Population A and C
        
             
        
        
        
Answer: Anything that has an Origin, composition, and texture. 
Explanation:
May be Minerals, feel rough or smooth, and can be hundreds or thousands of years old.
 
        
             
        
        
        
The answer is (B),coconut Palm trees grow up to 30m so it’s (B)
        
             
        
        
        
A sample is a random, unbiased selection out of a larger group. An independent variable is one that is changed as to see how it will affect the dependent variable in an experiment. 
Hope that helped.
        
             
        
        
        
Answer:
B. So you can always see the entire object at the higher magnification
Explanation:
A microscope is used to view objects smaller than the naked or unaided eyes can see. The objective lens, in conjunction with the occular or eye lens, is used to achieve this purpose. The objective lens are of different magnifications as follows: 10X, 40X, 100X etc. 
However, as the magnification increases i.e. higher objective, the object in the field of view becomes smaller and less focused. Hence, the object in the field of view must first be centered at a lower magnification/objective lens before changing to a higher one in order for the entire object to be seen at a higher magnification.