Either, carbon, hydrogen, nitrogen, oxygen, phosphorus, or sulfur. I would go with carbon because of the photosynthesis and cellular respiration<span />
Carbon is the most versatile element on the planet. It is found in all the living things and is recycled when the living beings die.
This element in the form of carbon dioxide is utilized by the plants to synthesize glucose (in which this element is also present) that is used in the form of food for the plants. The reaction for photosynthesis follows the equation:
It is also released by animals in the form of carbon dioxide as a cellular respiration product.
Apart from reminding oneself that you are prepared for the presentation. You can carry out a physical exercise like the breathing exercise by taking several deep breaths and exhaling to reduce nervousness. Also you should be mindful that the audience is there to hear you and not to judge you. In that way you can ease out tension.
