When a speaker alternately tenses and relaxes their muscles before speaking, this reflects a strategy of coping with nervousness that your text refers to as?

The answer to the given question is a coping strategy known as channeling your nervous energy.

Though you can choose to channel your nervous energy by keeping it to yourself, you can also exert it to your public speaking performance. Some ways of doing this include through creating interaction with your audience, speaking in a louder voice, and moving across the stage.

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.