It is less vivid; "raced after" emits a feeling of either action, suspense, or energy. It allows the reader to connect and fully understand what is going on. "ran after" is vague and emits little high energy.
Singular first person pronouns: I, me, mine, my, and we.
Plural first person pronouns: Our, ours, we, us.
You example them as an ‘immigrant’ because an immigrant is someone who comes from another country and moves to a different country.
I think it would be the one from paragraph 4, it shows laura has overheard what they were talking about and her mood changes and feels hurt
