How many independent variables can. e tested in a standard scientific experiment

This patient undergoes a gallbladder sonogram due to epigastric pain. the report indicates that the visualized portions of the liver are normal. no free fluid noted within morisons pouch. the gallbladder is identified and is empty no evidence of wall thickening or surrounding fluid is seen there is no ductal dilation. the common hepatic duct and common bile duct measure 0.4 and 0.8 cm respectively. the common bile ductmeasurement is at the upper limits of normal what cpt code in icd-10 cm code was used

In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?