[求助]谁能帮我分析一下这句话？谢谢！

漂亮宝贝

0108阅读25题:

Nevertheless, by the middle of the nineteenth century, the repid expansion of scientific knowledge and of public awareness---if not understanding---of it had created a belief that the advance of science would in some unspecified manner automatically generate economic benefits.

The word "it" refers t

1.understanding

2.public awareness

3.scientific knowledge

4.expansion

yvetta

我觉得答案应该是 3, scientific knowledge

句子主干是.....the rapid expansion of sicentific knowledge and (the rapid expansion) of public awareness of it    had created a belief........

因此，it 对应的不是expansion, 也不是public awareness, 更不是understanding, 而应该是sicentific knowledge.

漂亮宝贝

Thanks, yvetta!