同意 E B: At least as many as ... 但如果在1994, there were 100000000 jets produced. And last year, there were 999999999 jets produced. 這個結論還是成立 所以B不一定要對 如果B說 the number of jets produced last year was not significantly lower than the number in 1994. 還說的通.
重要的是要理解為什麼per production worker. 這只是個指標性的數字, 用來衡量廢氣排放量的, 並不表示廢氣是工人生產出來的 (當然是飛機生產的, 這點應該沒有疑問吧...)
base on this understanding, 再來看題目, 就會發現airplane manufacturer 有可能玩了個小把戲, 它的目的是要達到全年廢棄排放量減半, 而他用來衡量自己目標達到與否的指標卻被轉換成平均人均廢氣排放量. 那麼我們是否很有必要知道, 這個所謂的"人均", 前後各自到底是多少人呢? --> E
Goal: last year TOTAL production 小于 1/2*P1= x1 * 45才有可能达到减少1/2的可能。也就是说:x2*40<x1*45 . 如果像B说的(at least many last year ..as had produced in 1994) , 说明x2>=x1,那我们就无法判定x2 * 40 是不是小于 x1*45. 如果大于, 那goal 就没达到拉。所以是不成立的。
E取非:the number of workers in 1994 was significantly less than it was last year, suppose in 1994 the number is10, last year is 25, 10*90<40*25, then, the conclusion that the charges are false is weakened.