Molecules are the same element being held together by hydrogen bonds
compounds are different molecules being held together by different bonds
Answer:
D) epithelial tissue
Explanation:
The exchange surfaces of the organisms are the site for an exchange of substances or gases. These surfaces mostly lie within the body and protect the exchange tissues. The exchange surfaces of multicellular organisms are lined with epithelial tissues. These tissues have tightly packed cells with little or no intercellular spaces. The epithelial tissues serve to protect the exchange surfaces. Sometimes, these epithelial linings are modified to perform an additional function. The exchange surfaces are finely branched or folded to have a very large area. The digestive, respiratory, and excretory systems all have such exchange surfaces.
Answer:
the answer is B goodluck brainliest please
Explanation:
Viruses, diseases, are both possible answers
