Lack, want, need, require as verbs all stress the absence of something desirable, important, or necessary. Lack means to be without or to have less than a desirable quantity of something: to lack courage, sufficient money, enough
Most likely audience and purpose. It's not like there are timed applications and the way you write it is up to as long as it makes sense.
It adds emphasis shows how common it is for them
Answer:
the dog was frightened by the sudden noise
