Fill in the blanks: a. Simple organisms like sponges and coelenterates circulate �1� from their

Fill in the blanks: a. Simple organisms like sponges and coelenterates circulate �1� from their surroundings through their body cavities of facilitate the cells to exchange of `O_(2),CO_(2),` nutrients and waste products. b. More complex organisms used special fluids within their bodies to transport such materials. The ...2... is most commonly used body fluid by most of the higher organisms including humans for this purpose. c. Another body fluid ...3... also helps in the transport of certain substances.

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