Demonstrative pronoun is the answer.
The enzyme catalyzes (speeds up) the rate at which the substrate is broken down.
Your body needs two key nutrients: calcium and vitamin D. Calcium is the mineral that strengthens bones and teeth, and vitamin D helps the body absorb calcium while improving bone growth. So stuff like <em>yogurt, milk, salmon, tuna, and spinach.</em>
The answer is A or the first one
The correct answer is - They supply the energy needed for living processes.
Both the carbon and the nitrogen, are gases that are crucial for the survival of the organisms on the planet. They are mostly used by the producers in the ecosystems, as they need them to manage to perform their cycles, get nutrition, and of course energy. The producers are the basis of the ecosystems, so if they do not have a healthy supply of carbon and nitrogen, the ecosystems on the whole planet will collapse. The carbon and the nitrogen later go from one organism to another as the energy is transferred, and usually end up back into the atmosphere again.
