Question

Lymph from the left arm returns to the heart through the ____ vein

Answer 1

The answer for the above question is Thoracic duct. 
Lymph is a clear to white fluid made of; white blood cells, especially lymphocytes, the cells that attack bacteria in the blood. It also contains a variety of substances including proteins, salts, glucose, fats, water from the blood. Unlike blood it lacks red blood cells.