听力原文： Good morning, everyone. And welcome to the English for Academic Purposes Center. I'd like to begin by briefly introducing the services we offer here at our center. First of all, we have a wide range of language courses. In the first semester, we run an eight-way conversation class for students of non-English speaking backgrounds. We wish to improve their fluency, grammar and pronunciation in English. The course is held on Tuesdays between 12:30 and 1:30. So, that's one hour once a week. Please enroll with a secretary before Friday this week. For those of you who are interested in developing your writing skills, we have a six-week course which runs for two hours between 4 and 6 on Wednesday afternoons, beginning in week one. It concentrates on writing skills, needed for assignments in the department of economics and social sciences. Students must be enrolled in either of these departments. You are probably not thinking about taking an examination yet, but later on, towards the end of the term, you might like to enroll in our examination skills class. The course runs for five weeks and two hours in a week. The course deals with the skills you need in both written tests and oral examinations. It is not necessary to enroll before the course starts. Just turn up for the first class. Which course(s) runs or run for one hour each time?