They are all alone and they don’t have the same friend group, therefore they have to get out of their comfort zone.
Answer:
Anxiety
Explanation:
All the others are positive, but after WW1 Europe was not a happy place.
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
When trying to create unity and a good learning environment, the environment plays a very important factor.