When I arrived back home, I was met by my friends at the airport. My friends met me at the airport when I arrived back home. Be sure that adjectives and descriptive phrases refer to a specific noun or pronoun. Caught in the act, her excuses were feeble. By completing all the homework, chemistry can be better understood.
Students can better understand chemistry by completing all the homework.
Similarly, pronouns have to refer to a well-defined antecedent. The study of Roman history can lead one to believe that they were a violent people. In John Smith's essay, he makes a good argument against Wilamowitz. The study of their history can lead one to believe that the Romans were a violent people. OR One can be led to believe that the Romans were a violent people by studying their history.