Answer:
b
Explanation:
It is a fossil of sea shells
 
        
                    
             
        
        
        
It’s called Igneous .......................
        
                    
             
        
        
        
The classes of chordata which are warm-blooded are birds and mammals.
Explanation:
Warm-blooded animals are those which can maintain their body temperature at a constant.  
These classes of chordates balance their internal body temperature with that of the outer environment. When the outer environment is cold, they increase their internal temperature by producing more heat; and when it is hot outside they reduce their internal temperature by cooling themselves.  
The food consumed by a warm-blooded animal fuels to maintain a constant body temperature and hence they require more food.  
Warm blooded animals cool themselves with the help of sweat glands.  
The skin and other parts like fur in birds help to keep the animals warm during winter. Birds also shed their fur in hot season to keep them light. Birds migrate to warm regions during winter.
These animals have high stamina and energy to survive environmental changes. They maintain their temperature through endothermy, homeothermy or tachymetabolism.
Whale living in water is the fish which is also warm blooded because it is a mammal. 
 
        
             
        
        
        
The variable that researchers manipulate is the independent variable.
The reason for this is because in experiments different manipulations are often introduced. The sole purpose of these manipulations is to see whether they will affect our independent variable and if they will change its value. 
        
                    
             
        
        
        
The Southern Oscillation is in a negative phase when pressures are higher in Darwin than in Tahiti.
The Southern Oscillation Index (SOI) is a standardized index that is derived from the observed changes in sea level pressure (SLP) between Tahiti and Darwin, Australia. This index is used to predict future weather patterns. During El Nio and La Nia events, the SOI is one measurement of the large-scale fluctuations in air pressure that occur between the eastern and western tropical Pacific. These changes can be attributed to the Southern Oscillation. In general, when time series of the SOI are smoothed, a very good correlation with variations is seen in the temperatures of the oceans throughout the eastern tropical Pacific. The negative phase of the SOI indicates that the air pressure in Tahiti is lower than normal while the air pressure in Darwin is higher than normal. Extended periods of negative Southern oscillation index values coincide with ocean temperatures over the eastern tropical Pacific that are abnormally warm (cold), which is typical of El Nio (La Nia) events.
Learn more about El Nino here :
brainly.com/question/18307318
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