谢谢愚教授的批改！多费心了！

He might be the first person who mentioned that we should study science through observation and experiments in medieval times.

-- Where is the best place in the sentence for medieval times?
 
He might be the first person in Medieval Times ...?

this one is good.
or
mentioned in medieval times that ...?
or
we should study science in medieval times ...?

medieval times --> Medieval Times (noun for history period)

Anterior to Galileo, scholars believed .... -- Can you find a sentence that uses anterior the same way in which you use it?

No，I could not. 牢记在心。 

 

He carried two different sized stones which dropped on floor at the same time.

--

1. check the English definition for floor and ground
2. 他拎了两块大小不同的石头。两快石头同时掉到楼板上了?

floor不对。那能用ground吗？还是必须the earth？

It showed  his friends who went to see the experient with him that Aristotle was wrong.

-- It or Galileo showed to his friend that ...?

应该changed to Galileo（He）。

It was the spirit,  which Galileo testified our judgement and theories through nature directly, that led to ... --> It was the spirit, in which Galileo testified our judgement and theories through nature directly, that led to ...

怎么记住这个in which呢。该读哪部分语法，我可恶补一下？

谢谢愚教授！！！