Which of the following statements is (are) FALSE?I. Vertebrate blood is a type of connective tissue.II. Plasma is composed mainly of water.III. Most infectious agents we breathe in are filtered through the tonsils.IV. Lymph is returned to the circulatory system through ducts near the shoulders.

Statements I, II, and IV are true: blood is connective tissue, plasma is mostly water, and lymph returns to the bloodstream through ducts that drain near the shoulders. Statement III is false because tonsils help trap pathogens entering through the mouth and nose, but most agents breathed in are filtered or removed by defenses such as mucus and cilia in the respiratory tract—not by the tonsils. Therefore, the false statement is III only.

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