Good works!

 

Each component has a certain function, and it is structured in a special way to suit for the function, all the components rely on each other and cooperate with each other to fufill the task of the machine. --> split into multiple sentences ?

Consumption of the fuel has to provide power or engergy to the machine.  --> Consumption of the fuel has to provides with power or engergy to the machine.  Or --> Consumption of the fuel is needed to provide power or engergy to the machine.  ?

animal body is composed by various parts --> is composed of ?

digestive tract which digest and absorb food;   emunctory which get rid of the waste; --> digestive tract which digests and absorbs food;   emunctory which gets rid of the waste; ?