1. The letter was probably written for polemical impact. 这封信可能是为了造成争论性影响而写的。
2. The growth of communist economies was the subject of innumerable alarmist books and polemical articles in the 1950s. 20世纪50年代,共产主义经济的发展成了无数杞人忧天者的书籍和论辨者文章的主题。
3. Arguments cannot be solely polemical, but must derive from a clear, well-supported evaluation of the texts, lecture materials, videos or films. 论证不能仅仅是辩驳,必须来自于对课文、讲课资料、录影或影片的清楚且论据充分的评价。