请修缮这段文字要求表达要清晰语法要准确。This thesis takes the speech act theory as the theoretical framework takes the public service announcement language as the basis and uses the combination of text analysis and summa

This thesis employs the speech act theory as its theoretical framework and public service announcement language as its basis. It utilizes a combination of text analysis and summary to analyze the topic. Firstly, relevant literature and papers were searched, journals and books were consulted, and relevant websites were browsed to collect public service announcement language and gather information for the review. After reading a plethora of relevant literature, it was discovered that there were numerous research achievements on public service announcement language, but less research conducted from the perspective of speech act. Next, the thesis discusses the classification of speech act related to public service announcement, analyzes the types of speech act in public service announcement language, and summarizes the characteristics of speech act in public service announcement language. Lastly, the thesis concludes with a summary and recommendations, aiming to enhance the language skills and speech quality of public service announcement and achieve a more favorable "after words effect"