please help answer this question 13 - 27

(13) Using resources in ways that do not harm ecological systems that support human existence is referred to as (?). (14) Companies sometimes use (?) forecast methods based on judgment, opinion, past experience, or best guesses, to make forecasts. (15) (?) indicates how far into the future is forecast. (16) In time series data, a/an (?) variation is an up-and-down movement in demand that repeats itself over a lengthy time span (i.e., more than a year). (17) In time series data, alan (?) variation is an oscillating movement in demand that occurs periodically (in the short run) and is repetitive. (18) In time series data, a/an (?) variation is caused by unusual circumstances, not reflective of typical behavior. (19) In time series data, a/an (?) variation is a gradual, long-term up or down movement of demand. (20) In time series data, a/an (?) variation is the residual variation that remains after all other behaviors have been accounted for. (21) (?) is a moving average positioned at the center of the data that were used to compute it. (22) A/An (?) forecast uses a single previous value of a time series as the basis of a forecast. (23) (?) measures the fraction of time a piece of equipment is expected to be operational (as opposed to being down for repairs). (24) To increase the reliability of systems, (?) is added in the form of backup components. (25) (?) is the maximum theoretical output of a system in a given period under ideal conditions. (26) (?) is the capacity a firm can expect to achieve, given its product mix, methods of scheduling, maintenance, and standards of quality. (27) (?) forecasting methods are statistical techniques that make use of