Bullet comments were a way for viewers to send real-time comments or shares at the bottom or top of the screen while watching a video or live broadcast. In this case," Welcome to the series on why there are so few foreigners " might be an opening remark or title, but it should not be regarded as a formal program or content. As a fan of online literature, I think bullet comments are an interesting way to interact, but you have to be careful not to interfere with the viewing experience, especially when the content is tense or requires concentration. As for the question " Why are there so few foreigners?", it might just be a fictional series of stories that had no direct connection to the number of foreigners in reality. If this question is related to the actual problem, you can get a more accurate answer by searching for relevant information or consulting relevant experts.