A control is used to establish a baseline in an experiment.
hope it hepls
<span>A severe pain in the upper right abdomen associated with nausea and vomiting are the symptoms of choleithiasis. Fever, pain radiating from shoulder etc may also accompanies. The symptoms start usually after a heavy meal. This is a condition of inflammation of gall bladder.</span>
<span>Option B is correct answer.
The process of photosynthesis involves the splitting of water molecules.These water molecules provide free electrons to slipt the carbon from the carbon dioxide and then the final byproduct of this process is glucose and oxygen.</span>
Answer & explanation:
Gills are an adaptive structure for fish and other aquatic animals to survive in the aquatic environment.
They are blade-shaped and highly vascularized, allowing gas exchanges between the ambient water and the animal's blood.
Water enters the mouth and is led through the gills, being eliminated by gill slits, then oxygen is distributed in the blood to the animal's body.
