請依下文回答第 47 題至第 50 題：
Most progress against air-pollution has been cheaper than expected. Smog controls on automobiles, for example, were __47__ to cost thousands of dollars for each vehicle. Today's new cars emit less than 2 percent as much smog-forming pollution as the cars of 1970, and the cars are still as affordable today as they were then. Acidrain control has cost about 10 percent of what was expected in 1990, when Congress __48__ new rules. At that time, opponents said the regulations would cause a "clean-air recession"；__49__ , the economy boomed. Greenhouse gases, being global, are the biggest air-pollution problem the world ever__ 50__ .
【沉澱過後繼續努力】評論
Most progress agains☆ ☆☆☆-...
【Chiao Amy】評論
(A) predicted 預測(B) instructed 指示(C) described 描述(D) emphasized 強調
【我愛阿摩，阿摩愛我】評論
Smog controls on automobiles, for example, were predicted to cost thousands of dollars for each vehicle.例如，汽車煙霧控制預計每輛車要花費數千美元。
【海芋(逼自己自律)】評論
Most progress against air-pollution has been cheaper than expected.大多數空氣污染防治進展的成本都比預期的要低。Smog controls on automobiles, for example, were predicted to cost thousands of dollars for each vehicle.例如，汽車煙霧控制預計每輛車要花費數千美元。Today's new cars emit less than 2 percent as much smog-forming pollution as the cars of 1970, and the cars are still as affordable today as they were then.今天的新車排放的煙霧污染比 1970 年的汽車少了 2%，而且今天的汽車價格仍然和當時一樣便宜。Acidrain control has cost about 10 percent of what was expected in 1990, when Congress enacted new ...