Answer: Carbon dioxide, nicotine, carbon monoxide, tar, and alcohol. 
Explanation:
 
        
                    
             
        
        
        
Answer:
Self examination is the best term for this , it is a systematic observation and analysis of ones conscious experience. It normally happens when one feels is in a cross path situation and he is left in a dilemma not knowing which is the best direction to be taken.
 
        
             
        
        
        
Answer:
The abdominal muscles 
Explanation: The abdominal muscles are located between the ribs and the pelvis on the front of the body. The abdominal muscles support the trunk, allow movement and hold organs in place by regulating internal abdominal pressure.
 
        
                    
             
        
        
        
An inguinal hernia is a common condition in infancy and childhood, and is the most common surgical operation in childhood. An inguinal hernia occurs when tissue or part of the intestine pushes through a weak spot in the abdominal wall in the groin area, causing a bulge in the groin or scrotum.
        
                    
             
        
        
        
Answer:
Vertical allows people to nod, horizontal allows people to twirl
Explanation:
The vestibular system, which is key to our senses of balance, motion, and body position, is comprised of three semicircular canals connected to two membranous sacs called the saccule and utricle. The saccule and utricle are often referred to as the otolith organs. The otolith organs allow us to sense the direction and speed of linear acceleration and the position (tilt) of the head. The semicircular canals allow us to sense the direction and speed of angular acceleration. The semicircular canals are oriented along three planes of movement with each plane at right angles to the other two. Pilots and astronauts call these three planes of rotation pitch (<u>up and down; nod your head "yes")</u>, roll <u>(tumbling left or right; move your head from your left to your right shoulder or vice versa)</u>, and yaw (<u>lateral movement left and right; shake your head "no").</u>