Digestive enzymes<span> speed up reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive </span>enzymes<span>, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they </span>need<span> to </span><span>survive</span>
        
             
        
        
        
Soaring and gliding birds like eagle, vulture, albatross, sea gulls etc are efficiently adapted to utilize the air currents in their flight. 
Explanation:
The soaring flight and gliding movements are special adaptation developed by birds to meet the challenge of increasing turbulent air current.
Birds have the extraordinary skill of flying smoothly and effortlessly even at very high altitudes  
Birds soar by using thermal and dynamic soaring techniques.
Gliding movements help the birds to deflect the wind downward which helps to lift their bodies in the air. They do not flap their wings during gliding but just dive straight into the air which helps to increase their speed.
The adaptation of the bird’s structure with very light but strong bones on their wings helps to soar and glide in the air.
 
        
             
        
        
        
Answer:
D. A brown gas produced
Explanation:
When a chemical reaction occur, there are several changes that takes place such as change in color, odor change, formation of a gas, and formation of a precipitate etcetera.
In the given chemical reaction, two colorless gas (NO and O2) react together and form brown gas (NO2). So, the change of gas from colorless to brown gas is the evidence that shows chemical reaction occurred.
Hence, the correct option is "D. A brown gas produced".
 
        
             
        
        
        
<span>gazelles, zebras, rhinoceroses, wild horses, lions, wolves, prairie dogs, jack rabbits, deer, mice, coyotes, foxes, skunks, badgers, blackbirds, grouses, meadowlarks, quails, sparrows, hawks, owls, snakes, grasshoppers, leafhoppers, and spiders.
</span>
        
             
        
        
        
Temperature can cause an enzymes shape and function to alter due to the fact that once an enzyme reaches its optimum level, if it goes over it begins to denature. If the temperature is below optimum, then an enzyme will work at a slower rate.  Also, the pH can affect an enzyme.