Answer:
They protect you against illness and disease. Think of white blood cells as your immunity cells. In a sense, they are always at war. They flow through your bloodstream to fight viruses, bacteria, and other foreign invaders that threaten your health.
The answer is c. last time i had that and my teacher said it was c
In the case of liquid droplets, including water, surface tension is the factor, which is accountable for their shapes and configuration. Though can easily be malformed, the droplets of water seem to be pulled into a spherical shape due to the cohesive forces of the surface layer.
In the non-existence of other forces, involving gravity, the drops of almost all the liquids would be almost spherical.