By __________ a cheaper material for the steel in our products, we can greatly reduce manufacturing costs.

2023-05-26

A.substituting
B.replacing
C.alternating
D.displacing

参考答案:A

句子表示“用更便宜的材料代替钢铁”,意为“用A代替8”的词组"substitute A for B”放在空格处的句意最自然,故选A。