Answer:
 Source of current, force and pathway.
Explanation:
 Source of current, force and pathway are the three important things needed or responsible for the current flow. A supply of electric charges (electrons) which is provided by the electric source, force of push to move the charges through the circuit and a pathway on which current flows. Without these three things, flow of current is impossible. so we can say that the situation in which all these three things are present will allow the current to flow in the circuit.
 
        
             
        
        
        
It should be Ozone, hope that helps. 
Trees release CO2 which is Oxygen.
Plants release water vapor through Photosynthesis. 
        
                    
             
        
        
        
Answer:
False 
Explanation:
In eukaryotes apart from RNA polymerase, the transcription of genes requires many different proteins called transcription factors. These transcription factors are important to initiate and regulate transcription.
There are two types of transcription factors regulatory and basal transcription factors. Basal transcription factors regulate transcription by binding to a gene promoter and regulatory transcription factor regulates transcription by binding to some regulatory sequences for example enhancers and silencers.  
Therefore only basal transcription factor binds to the promoter for regulating transcription. Therefore the statement is false.
 
        
             
        
        
        
689 decilitres =
68900 millilitres