through and out -

[arthurshen]

we have read the story of the terrific struggle through and out of which the present civilization has grown.

what does through and out mean here?

can anyone please rewrite this sentence in a form without using which?

[Temico]

we have read the story of the terrific struggle through and out of which the present civilization has grown.

The above is a compound sentence made up of two sentences:-
a) We have read the story of the terrific struggle through which the present civilization has grown.
b) We have read the story of the terrific struggle out of which the present civilization has grown.

If you don't want to use "which", you can write the sentence this way:-

"We have read the story of how the present civilization grew out of a terrific struggle."