Correct answer: Greenhouse effect.
        
             
        
        
        
Sulfur emissions from industry combine with water in the atmosphere and form acid rain. A new factory is built very close to the lake that Josh visits often. By examining the table that shows what pH range different species can survive, Josh decides that the aquatic life will be affected by the changes in pH that the lake. Josh correctly decides that organisms that will be the most affected are 
A)	perch and frogs.
B)	mayfly and bass.
C)	snails and clams.
D)	frogs and salamanders.
The correct answer is option (C) snails and clams.
Acid rain is formed when oxides of sulfur and nitrogen combine with water molecules. Industries are one of the major contributors to acid rain. pH is a measure of acidity or alkalinity in water. 
A factory built close to the lake can cause acid rain which affects the pH of the lake. Any change in the pH of the lake has an effect on the organisms in it. A pH of 7 is considered to be neutral and pH values below 7 indicates acidity and pH values above 7 indicates alkalinity. Organisms have an acid tolerance level beyond which they are affected and can die. Perch has an acid tolerance of up to pH 4.5 and frogs can tolerate an acidic pH of 4.0. The acid tolerance level of Mayfly and Bass is a pH of 5.5. Salamanders can tolerate an acidic pH of 5. Whereas, Snails and Clams have a very less pH tolerance of 6. They are highly susceptible to acidic pH. 
Thus, Josh correctly decides that organisms that will be the most affected are snails and clams. 
 
        
                    
             
        
        
        
Answer:i think its C or D
Explanation:
It cant be chemoautotrophs or photoatropus
 
        
             
        
        
        
When humans farm large plantation of one cash crop, they reduce the biodiversity of the region because they reduce the genetic diversity of the species in the environment. A reduction in genetic diversity means that the genetic variability of the species is reduced  hence there are fewer sub-species in the environment. This ultimately reduces the biodiversity of the ecosystem -  which is the variability among all the living organisms in the environment. 
 
        
             
        
        
        
There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.