Answer:
The correct answer is - leads.
Explanation:
In ECG or electrocardiogram, a test that is used to measure the electric activity of the heart of an individual, each electric impulse cause a electric wave to travel through the heart and cause the heart pump to pump blood. 
There are electrodes that received the electric impulse in this machines, electrodes have self adhesive pads and attached with various leads mostly 12, that carries the impulses in the combinations that are recorded on the ECG.
Thus, the correct answer is - leads.
 
        
             
        
        
        
Transpiration occurs on plants. So the answer is D. Leaves
 
        
             
        
        
        
Answer: Homeostasis refers to the body’s ability to maintain a stable internal environment.
Explanation: Maintaining homeostasis requires that the body continuously monitors its internal conditions.
Hope this helped! :)
 
        
             
        
        
        
Answer:
 A) Resources become scarce.