Answer:
Explanation:
Aftershocks are earthquakes that follow the largest shock of an earthquake sequence. They are smaller than the mainshock and within 1-2 fault lengths distance from the mainshock fault.
Foreshocks are relatively smaller earthquakes that precede the largest earthquake in a series, which is termed the mainshock.
 
        
                    
             
        
        
        
The  length of a vessel  is directly proportional to its resistance: the longer the veessel, the greater the resistance and the lower the flow. As with blood volume, this makes intuitive sense, since the increased surface area of the  vessel  will impede the flow of blood.
 
        
             
        
        
        
B ~ You cannot tell if someone was touching your hand
Hope this helps! ^^
 
        
                    
             
        
        
        
Answer:
1. Signaling molecule
2. Signaling receptors 
Explanation:
Hormones, growth factors, neurotransmitters, etc. serve the function of signaling molecules for cells. These molecules are released by one cell and bind to the receptors present on/in the target cells to elicit the desired response. Thereby, the signaling molecules serve in cell-cell communication. 
For example, insulin hormone synthesized and released from beta cells of pancreas binds to its cell surface receptors present on the surfaces of liver cells and muscle cells to stimulate the uptake of the glucose from the blood.  
Likewise, neurotransmitters released from the presynaptic neuron bind to receptors present on the membrane of postsynaptic neuron and serve to carry the nerve impulse to the postsynaptic neuron.