Answer:
The correct answers are first in sentence 9 and old in sentence 11.
Step-by-step explanation:
Redundant expressions are those expressions that are unnecessary within a sentence because they either do not add any new meaning or they just repeat what was already stated.
In sentence 9, you don't have to say first introduction because the word introduction on its own means that something is happening for the first time.
In sentence 11, you don't have to say old antiques because the word antiques already means something old, so there is no need to say it twice.