Ventricular systole and Ventricular diastole. (Type of heart sound produced)

Explanation

### Step-by-Step Solution:

1. **Understanding Heart Sounds**: The human heart produces two primary sounds during its cycle, known as S1 and S2. S1 is often referred to as "lub," while S2 is referred to as "dub."

2. **Identifying the Phases**: The heart goes through two main phases:
- **Ventricular Systole**: This is the phase when the ventricles contract to pump blood out of the heart.
- **Ventricular Diastole**: This is the phase when the ventricles relax and fill with blood.

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