Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.

It is not known how much, if any, of this story is true, but historians do know that China was the first civilization to use silk.
It is not known if the story is true. However, historians know China was the first to use silk.

Bonham Carter made her film debut in the K. M. Peyton film, A Pattern of Roses, before appearing in her first leading role in Lady Jane.
Bonham Carter played her first role in the K. M. Peyton film, A Pattern of Roses. Than she played her first leading role in Lady Jane.

The Victoria Hall remained in use until 1941 when it was destroyed by a German bomb.

Victoria Hall was used until 1941 when it was badly damaged by a bomb planted by Germans.

