Blood is a collective uncountable term, but in the sense of tribes or tribal members, it could be "bloods" -- but this would have very rare and specific uses.
Example:
The chicken coop showed traces of chicken, dog, and cougar blood. (not bloods)
The plural form of "blood" is "bloods."
The plural form of blood is blood.
The plural form of the word atrium is atria. The atria are the two upper cavities of the heart from which blood is passed to the ventricles.
The plural form of thrombus is thrombi.The plural is "thrombi" (from Latin), meaning blood clots within a blood vessel, or in the heart. If a blood clot reaches the lungs, it can cause pulmonary thrombosis.
The plural form of "thrombus" is "thrombi." A thrombus refers to a blood clot that forms in a vessel, and when multiple such clots are present, they are collectively referred to as thrombi.
There is no plural form. Do and Do not are verbs
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
The plural form of "is" is "are."
The plural form of "I" is "we."
The plural form of "was" is "were."
The plural form of mouth is mouths. The plural form of month is months. The Mounth is a range of hills in Scotland and does not have a plural form.