___raw materials into useful products is called manufacturing .
问题描述：
___raw materials into useful products is called manufacturing .
A transform B transforming C being transformed D when transforming
答
___raw materials into useful products is called manufacturing.
A transform Btransforming C being transformed Dwhen transforming
答案：B
解析：题干的主句为XX is called manufacturing 所以填入的内容得做句子的主语成分,动词原形不能做主语,A排除,D选项是时间状语,也不能做主语,排除.此处transform into是“把……变成……”的意思,根据句意,用主动态,直接加ing即可.
句意：把原材料变为有用的产品（的过程）就被称为制造.
有问题请追问.我就是有点不明白这儿为什么要用主动语态那么 被动语态你觉得合适吗？这里是XX把原材料变成产品啊，raw materials是transform的宾语啊~你可以自己再加个主语，比如说“人们”，人们把原材料变成产品，这样不就是主语吗？懂了吗？