Answer:
 Pericardial sac has protective tole
Explanation:
Pericardial sac or pericardium is a fibrous tissue that surrounds the heart. It has two coats:
- the outter coat-parietal pericardium
- the inner coat-visceral pericardium or epicardium which is double-layered and contains pericardial fluid between those two layers (pericardial fluid is necessary as a lubricant for the heart movement).
Besides lubrication, percardium also protects heart from infections, fixes it and limits its movements.
 
        
             
        
        
        
The correct answer is (d.) proteins. Higher organisms use nitrogen to make their protein. Food that is containing protein also involves nitrogen in it. Protein also has amino acids that contain nitrogen in it which is a necessary essential nutrient for the body.
        
                    
             
        
        
        
Whales have horizontally positioned tales opposed to fish and they swim in an up and down type of motion to move, where as fish are the exact opposite flexing and turning their body left and right with their vertical tale to move.
Whales have bigger mouths to eat large schools of krill (their main source of food)
And also, whales are mammals, and breathe with their lungs, whereas fish use gills to breathe underwater. I hope this helped! Please mark Brainliest!
 
        
             
        
        
        
just know about super power 
what is renewable power¿¿
 
        
             
        
        
        
Answer:
Heat causes liquid and frozen water to evaporate into water vapor gas, which rises high in the sky to form clouds.
Explanation: