Sentence example:
1) The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic peoples has been established by carbon dating, but what is much more difficult to determine is the use TO WHICH primitive peoples put the caves, the reason for their decoration, and the meaning of the magnificently depicted animals.
Or
2)
if you look at this post: https://www.manhattanprep.com/gmat/foru ... t1277.html
StaceyKoprince wrote: make up the extended noun phrase TO WHICH "which" refers
3)
According to public health officials, in 1998 Massachusetts became the first state IN WHICH more babies were born to women over the age of thirty than under it.
4)
In an effort to reduce the number of fires started by cigarettes, a major tobacco company is test-marketing a cigarette in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing the rate AT WHICH it burns and lowering the heat it generates.
I saw a lot of structures like these examples. They are using different prep in front of WHICH. Confused on this structure.
So how to understand the TO/IN/AT WHICH here in these sentences?
1)
I knew that TO is part of the intransitive verb phrases "refers" or "put", but for some reasons they were moved to the beginning of the noun modifier(am I right for noun modifier, or adverb modifier?), I don't know why they moved. Can anyone help to explain?
2)
And what role do these WHICH play? They are not simply "in which = when" or "at which = when."