Ans. 
Paper waste prevention is defined as a practice to reduce or eliminate use of paper, which is potential for the efficient use or disposal of paper. It decreases the environmental impacts due to both paper manufacturing and paper recycling, such as demands on forest resources).
Use of advance technologies, such as E-mail (electronic mail) can help in cut down on paper waste. Nowadays, E-mail has replaced conventional letters and faxes as it is more eco-friendly than letters and faxes, which needs paper consumption. 
Thus, the correct answer is 'option d). E-mail.'
 
 
 
        
                    
             
        
        
        
Answer:
The monomers of DNA are individual nucleotides: cytosine,  guanine, adenine, and thiamine,  (A, T, C, G, respectively). Since DNA is a double-stranded molecule, each nucleotide has a match that chemically interacts with it to form nucleotide pairs
Explanation:
 
        
             
        
        
        
The correct answer is by facilitated diffusion.  
The procedure of continuous passive transport of ions or molecules through a semi-permeable membrane with the help of particular transmembrane integral proteins is known as facilitated or passive-mediated transport or facilitated diffusion.  
It is a modification of osmosis incorporating a proteinaceous channel via which an extracellular solute can enter a cell in the absence of energy.  
 
        
             
        
        
        
Answer: 
D. four haploid cells
Explanation:
When meiosis is complete,four haploid cells are formed from a single diploid cell. The four daughter cells produced that contains half the number of chromosome than that of their parent cell. Due to meiosis the number of chromosomes remain fixed in a species from generation to generation.
The process results in four daughter cells that are haploid, which means they contain half the number of chromosomes of the diploid parent cell. Meiosis has both similarities to and differences from mitosis, which is a cell division process in which a parent cell produces two identical daughter cells.
 
        
                    
             
        
        
        
Answer:
Pick Hydrogen, but read below.
Explanation:
The blacks are Carbon. They have 4 connections. The left Carbon has 3 whites connected to it. It is not totally an exclusive answer, but the whites could be anything in Column 17 (F, Cl, Br, I) or Hydrogen. Likely it is hydrogen.