Answer:
The three R's – Reduce, Reuse and Recycle – represent the best strategy for conserving non-renewable oil, coal and natural gas. ... Increasing the reliance on renewable energy sources, such as solar, wind and geothermal generators, can also help conserve the dwindling supplies of fossil fuels that remain in the ground.
Explanation:
 
        
             
        
        
        
If you’re trying to figure out if it’s true or false it’s true
        
                    
             
        
        
        
Important muscle electrical signals is the movement of charged material (ions) across cellular membranes in a limited area
        
             
        
        
        
Answer:
47 
Explanation:
We all know that gametes like egg cell and sperm have haploid set of chromosomes but here as per this question she has produced 2 copies of chromosome 21. For the sake of maintaining haploidy, she was supposed to have only a single copy of chromosome 21 as a result of which her egg cell was supposed to have 23 chromosomes not 24. 
But, this is a case of non dis-junction. Also, in a normal sperm there are no such copies of any chromosome i.e. there is a haploid set of chromosomes. It means that sperm must be having only 23 chromosomes. So we can easily infer that when the egg cell and sperm will fuse, the zygote will have 47 chromosomes (24 from egg cell and 23 from sperm).  
 
        
             
        
        
        
The Neural Stem Cells. Hope this helped!