问题补充：
Paper bags produced every year are the world’s production of vehicles.
A. three times weight of
B. three times the weight of
C. as three times heavy as
D. three times as heavier as
答案：
A. three times weight of
(答案→)B. three times the weight of
C. as three times heavy as
D. three times as heavier as
解析：考查倍数表达法。考查倍数被动法。倍数表达有四种：1. “A+倍数+形容词或副词的比较级+than+B”， 2.“A+倍数+as+形容词或副词的原级+as+B”， 3. “A+倍数+the size/height/length/width， etc+of+B”， 4. “……times+what+从句”。倍数永远都放在最前面。句意：每年生产的纸袋的重量是汽车重量的三倍。故B正确。
