Answer:
its either a or b i don't know exactly cuz I didn't learn this but I tried looking it up and it didn't work
 
        
             
        
        
        
Answer:
approximately 860 light-years (260 pc) from Earth
 
        
             
        
        
        
Answer:
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
Explanation:
 
        
             
        
        
        
Answer: A. Research into a phytochemical from a plant which might inhibit cancer development.
Explanation:
The chemoprevention is a process of utilization of chemical formulations such as medication, supplements and vitamins to the stop the growth of cancer cells. This is necessary and important for people which are at high risk of developing cancer. 
The research for the phytochemical derived from the plants can be an example of chemoprevention as this will help in inhibiting the cancer development. 
 
        
             
        
        
        
Answer:
The correct answer is "altering the equilibrium of ecosystems".
Explanation:
Ecosystem have a very complex and sometimes intricate equilibrium. Each species in an ecosystem have a role in the food chain, therefore, if humans affect the behavior of one species, undoubtedly, another species will be affected. In this case, insect populations are increasing as a result of birds modifiying they migratory behavior due to the presence of discarded food in the landfills. Most likely the increased insect populations will affect the plants population as well, creating a series of events that alter the equilibrium of the ecosystems.