Contingent valuation is based on surveys of the " disutility " of death at different ages .
条件价值评估是基于不同年龄段的“负效用”死亡的数项调查。
Assume also that putting up the tree and taking it down bring disutility , although in my experience this is not necessarily the case .
同时假定，把树装饰起来和拆掉都会带来负效用（尽管就我的经验来看，情况未必会这样）。
Evacuees are allowed to re-select their target exits with their movement during evacuation . In each exit choice , evacuees select exits , from which they pay the least perceived disutility for leaving .
