At central high school they ring a bell to end every class period. sometimes, by mistake, they ring the bell in the middle of a class period and teachers find that many of their students get up to leave not realizing that only about half of the class time has gone by. the students have learned this behavior via

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.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer