处理机调度可分为三级，它们是高级调度，（）和低级调度；在一般操作系统中，必须具备的调度是（）.

听力原文：W: English Language Center. How may I help you?M: Yes. I'm calling to find out more information about your program. For example, what kind of courses do you offer?W: [20]Well, first of all, the purpose of our program is to provide language learning opportunities for this area's community, whether a student's goal is to master basic functional language skills, let's say, for his or her job, or to study intensively to enter a US college or university.M: Okay. I'm calling for a friend who is interested in attending a US university.W: [19]And that's the kind of, uh, instruction that we provide, from basic communication courses to content- based classes such as computer literacy, intercultural communication, and business English.M: Great. What are your application deadlines for the next semester?W: Well, [21]we ask applicants to apply no later than two months before the semester begins. This gives us time to process the application and issue the student's 1-20.M: An 1-20?W: Oh, an 1-20 is a form. that indicates that we are giving permission for the student to study in our program, and then the student takes this form. to the US embassy in his or her home country to apply for the F-I student visa.M: All right. What is the tuition for a full-time student?W: [22]It's two thousand thirty dollars.M: And how does one apply?W: Well, we can send you an application and you can mail it back to us, or you can fill out our application that's on our Web site.(23)A．To help international students prepare to enter institutions of higher learning.B．To teach students how to use English in their daily lives and at work.C．To provide work opportunities for graduating students in the community.D．To provide, from basic communication courses to content-based classes. 点击查看答案

Genera Technologies has developed a method that determines whether water is clean.（）

A.Right
B.Wrong
C.Not mentioned

点击查看答案&解析