Answer:
Can't be heard
Explanation:
The prefix in- means not, and "audible" basically means hearable. Put them together and you get not hearable, or can't be heard!
This isn't neccessarily true. Your introduction can still make sense without the hook, and the information inside the introduction part should really not directly depend on the hook to explain them, they should either be self explanatory, or you should explain them there.
Hopefully this helps!
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