Answer:
D) What is the best amount of sunlight for mustard plants.
Notice she changes how much light each plant is exposed to.
Explanation:
 
        
             
        
        
        
Answer:
The correct answer is B)10%. See the explanation below, please.
Explanation:
We use the following equivalence, remembering that Adenina pairs with Timina and Guanina with Cytosine:
A=T   ; C=G   A+G=T+C
If A= 40% ----> T=40%
A+G=T+C
40%+G= 40% +C   ---->  40+10=50
G=C=10%
 
        
             
        
        
        
Answer: C. It provides information about what is already known about a particular research question.
Background research is a research which is done before designing a new research plan. This involves a review of complete history and nature of research problem with respect to the existing literature. Therefore, background research provides  already known information about a particular research. 
 
        
                    
             
        
        
        
Answer:
I only know a few 
1. aluminum
5.copper
4.zinc
2.sulphur ( specifically vulcanization of sulphur )
 
        
             
        
        
        
B and c
Its because heavier objects have a higher gravitational force