prep sc (prep 2-107 edited by aeoluseros)

kun861010

116. Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he quickly built his own device from an organ pipe and spectacle lenses.

A. Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he

B. Galileo had not invented the telescope, but when he heard, in 1609, of such an optical instrument having been made,

C. Galileo, even though he had not invented the telescope, on hearing, in 1609, that such an optical instrument had been made, he

D. Even though Galileo did not invent the telescope, on hearing, in 1609, that such an optical instrument had been made,

E. Even though Galileo did not invent the telescope, but when he heard, in 1609, of such an optical instrument being made, he

答案是a，但是that不能这么用吧？这里就让我想到了，什么错误属于effectiveness 错误，什么属于correct错误啊，那个应该优先排除，哪个应该其次排除呢？

aeoluseros

为什么不能这么用呢?
in 1609是插入语，不影响句子结构的。

kun861010

不是只有，which吗？that应该紧接宾语之后的吗？
我看的是prep语法笔记，不知道那个数字2-107怎么来的。。。。。

zwhjzwhj

我不明白这是什么用法。

语法笔记上说：“on hearing that…作为时间状语修饰but引导的表转折的从句；that为同位语从句，表示hearing的具体内容；in 1609为插入语，表hearing的时间。”

这个hearing是什么东西？动名词么？有on 动名词这样的用法做时间状语？比如说：on watching，on buying？
还有，这个that是定语从句的关系代词？修饰hearing这个动名词？

2643301345

on 是介词

阿拉梦

on hearing that加从句，后面再来个主句，表示“一听说XXX，就YYY”