City service will separte enough refuse for recycling purposes in order to reduce the total number of truckloads of refuse sent for inceineration by half. The intent is to convert at least half of the refuse for recycling in order to cut the total amount for incineration/burning in a year.
If you read carefully, you would notice a scope shift from "the amount of residual ash" to "the number of truck loads." For the conclusion to hold, D has to be true, since it connects "amount of ash" to "truckload."
-- by 会员 sdcar2010 (2011/3/26 7:11:43)