Answer:
A catalyst is a substance that can be added to a reaction to increase the reaction rate without getting consumed in the process. Catalysts typically speed up a reaction by reducing the activation energy or changing the reaction mechanism. Enzymes are proteins that act as catalysts in biochemical reactions
Explanation: I don't know if this will help but hopefully it does 
 
        
             
        
        
        
Which of the following organisms is not nekton? a. Whales
 b. Crabs (answer)
 c. Sharks
 d. Dolphins 
        
                    
             
        
        
        
The amount of gravitational pull helps determine the gases that can form an atmosphere around a large body in space. So the mass of an object also determines the density of these gases. Note that several factors come into effect for a large object to sustain their gases if present.
        
                    
             
        
        
        
Answer: c. Point B has an elevation less than 2750 feet.
Explanation:
The lines drawn on the map are known as contour lines and they are used to measure elevation. Point B is on a river and rivers are only able to flow at a lower elevation than the area around them. 
Point B is therefore lower than the area around it and as the closest contour line to it puts the area at an elevation of 2,750 feet, that must mean that Point B is lower than 2,750 feet. 
 
        
             
        
        
        
1- C ( this is an assumption; a hypothesis is always based on an assumption.
2- F ( this states to share the results with other classmates).
3- D (this is a description of an experiment you could conduct; you test a hypothesis (usually) by conducting an experiment.
4- A (this is something you could observe during the experiment, therefore it is an observation).
5- E (this sentence is a conclusion).
6- B (This is an actual question)