答案:Nowadays, it has become very common in colleges and universities for students to grade teachers. In some universities, students’ rating has even become the only source of assessment on teaching effectiveness. This, however, has caused great controversy. Some are in favor of the rating system. They hold that since students attend the teachers’ classes every day, they might be the best people to judge their teachers’ teaching. In addition, students’ rating can also encourage teachers to improve their teaching, thus helping to form a harmonious relationship between teachers and students. Others, on the contrary, are strongly against it. They argue that students do not have the necessary knowledge and skill to make sound judgments about course content or teaching style, and their rating would be both unreliable and invalid. In my opinion, students’ rating of their teachers is quite necessary, but it should be conducted in a way that can really reflect teachers’ performance. Instead of rating the teachers’ knowledge on the subject, students should be asked to estimate their teacher’s ability to communicate with students, his or her relationship with students, and what they have learned from the teacher in a course.