Some blood cells responsible for the transportation of oxygen and other are there for rebuilding of tissues. Fights things the body doesn't recognize
        
             
        
        
        
Answer:
The answer is both  the first (Cause disease) and second (Cause algal blooms)
Explanation:
Protists may cause disease and even kill living things. Also, algal blooms are essentially protists but have chloroplasts- which plays a part in them being harmful.
 
        
                    
             
        
        
        
A dam is a structure built across a stream or river to hold water back. Dams can be used to store water, control flooding, and generate electricity.
        
                    
             
        
        
        
Answer: I think the answer is c
Explanation: