Final answer:
The commonly used sites for intravenous injection are the Antecubital vein and Basilic vein.
Step-by-step explanation:
The commonly used sites for intravenous injection are the Antecubital vein and Basilic vein. The Antecubital vein is located in the antecubital region and is frequently used for drawing blood. The Basilic vein runs medially and superficially through the arm and is commonly used for venous access.