The answer to this question is <span>variable-ratio schedule
</span><span>variable-ratio schedule refers to a schedule of reinforcement in which the response is being reinforced. after an unperdictable amount of response is being made.
The purpose of this type of scheduling is to create a high rate of responses.
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Adults need at least 150 minutes of moderate-intensity physical activity and should perform muscle-strengthening exercises on 2 or more days each week.
2. When the left ventricle relaxes, the aortic valve closes and the mitral valve opens. This lets blood flow from the left atrium into the left ventricle.
4. Quickly shocking the heart with an automated external defibrillator (AED) can save a person's life after cardiac arrest. An AED is a portable, battery-operated device that a bystander can use. It checks the heart rhythm and can send an electric shock to the heart to try to restore a normal rhythm.
5. High blood pressure can damage your arteries by making them less elastic, which decreases the flow of blood and oxygen to your heart and leads to heart disease. In addition, decreased blood flow to the heart can cause: Chest pain, also called angina.
hope this helps :)
C. nose .......................................
Answer:
B. antiretroviral therapy
Explanation:
these are drugs that are degined to improve the immune system of the patient to enable resistance to other pathogens
