I need your help to check these sentences, Writeacher. Thank you very much in advance.

1) Winston's face is ruddy for the low quality soap and blunt razor blades he uses.
2) His face is ruddy for the use of low ..(Which one is best?)
3) Everything seems colourless except for the posters of Big Brother, which are plastered everywhere.
4) The telescreen receives and transmits simultaneoulsy.
He wonders whether/if there have always been rows of dilapidated houses.
5) Rats are waiting to eat Winston.
O' Brien, that is a member of the party, admits that he wrote the large part of G.'s book.
6) He couldn't stand the humiliating corporal punishment to which Eaton's students were subjected to. (students at Eton).

Writeacher is on vacation for a week or so.

1. is better. I'd substitute "because of" for "for."

4. Either "whether" or "if" is ok.

5. Use "who" instead of "that" in the first clause.

6. Both are correct.

I'd be happy to help you check these sentences. Here are some suggestions for each sentence:

1) Winston's face is ruddy because of the low-quality soap and blunt razor blades he uses.
2) His face is ruddy due to the use of low-quality soap and blunt razor blades.
3) Everything seems colorless except for the posters of Big Brother, which are plastered everywhere.
4) The telescreen both receives and transmits simultaneously.
He wonders if there have always been rows of dilapidated houses.
5) Rats are waiting to eat Winston.
O'Brien, a member of the party, admits that he wrote the majority of G.'s book.
6) He couldn't stand the humiliating corporal punishment to which the students at Eton were subjected.

Overall, the corrections I made were minor and mostly involved improving word choice, sentence structure, and clarity. Always be mindful of proper punctuation and grammar while writing.