Answer
Pimples are caused from an accumulation of sebum blocking an oil gland duct. When these ducts are blocked, whiteheads appear. If this whitehead oxidizes and dries, a darked blackhead will appear.
Work Step by Step
Pimples are caused from an accumulation of sebum blocking an oil gland duct. When these ducts are blocked, whiteheads appear. If this whitehead oxidizes and dries, a darked blackhead will appear.