第一，马上去找个老外向他请教，他可能会给你出谋划策，也帮你练练口语。
　　第二，把老美可能提的问题列出来，并写出答案，反复练习。

　　可能提的问题是：
　　1. Why are you interesting in ***University?
　　2. Why are you going to USA not staying your homeland to study?
　　3. What is your major now? Say something about your work, etc.
　　4. What is your favor? (maybe)
　　5. Who is the great person in the world in your eyes?

　　At the beginning if you cannot hear clearly about the words from Prof., you can tell him/her "Please speak loudly for my phoneline is not clear" (maybe the sentence is not correct, but it is the similar meaning), then he/she maybe speak loudly and slowly. At the end you can say "Thank you for calling!".