Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air<span> by a system of </span>air<span>-filled </span>tubes<span> called tracheae. Tracheae open to the outside through small holes called spiracles. In the</span>grasshopper<span>, the first and third segments of the thorax have a spiracle on each side.</span>
        
             
        
        
        
<span>The parts that explicitly support that ideal are where he says that he calls "not upon a few, but upon all" and where he says that "the city and the country, alarmed at one common danger, came forth to meet and to repulse it." To me, that is saying that he is calling upon everyone to potentially sacrifice their life to obtain a goal that they believe is worth that cost.</span>
        
                    
             
        
        
        
Answer:
The author's purpose for writing this sentence is describing the process that goes into prepping for a marathon. 
Explanation:
This is reflected because it lists a step in that process of training for the race mentioned in the first part of the sentence "before the race" 
 
        
             
        
        
        
The answer is probably when. What are the options