Answer:
because it would be dangerous to do it by hand or skin.
Explanation:
 
        
             
        
        
        
Answer:
The answer is C.
Explanation:
At first, an enzymes called Helicase unwind the double helix in a DNA .
 
        
             
        
        
        
Answer:
A
Explanation:
Thick clouds can trap lots of heat. This has a warming effect on earth.
 
        
             
        
        
        
Superior vena cava- upper body inferior vena cava
lower body- bother drain into the right atrium
        
             
        
        
        
Answer:
Intervertebral foramen
Explanation:
These structures are found in between pairs of vertebrae  and not only do spinal nerves pass through them, the spinal artery, veins, and transforaminal ligaments do too. While the spinal cord passes through the vertebral foramen, the spinal nerves exit and enter the spine through these intervertebral foramen to 'serve' the rest of the body.