Add punctuation: In this historical center there are churches cathedrals temples and theaters that were built at the beginning of the last century and have survived in an excellent condition
A: In this historical center there are churches, cathedrals, temples, and theaters that were built at the beginning of the last century and have survived in an excellent condition.

Add punctuation: His chair of pure mathematics was however a little unfortunate as Jeffrey had to leave many parts of that subject to his assistants
A: His chair of pure mathematics was, however, a little unfortunate as Jeffrey had to leave many parts of that subject to his assistants.

Add punctuation: Pixwords The image with jewelry glass necklace Agencyby
A:
Pixwords The image with jewelry, glass, necklace Agencyby