在Visual FoxPro的菜单设计器中,用来设置访问键的字符标志是______。
查看答案
23~24 题基于以下说明。设有三个关系: 学生关系S(SNO,SNAME,AGE,SEX) (分别代表学生的学号、姓名、年龄、性别) 学习关系SC(SNO,CNO,GRADE) (分别代表学生的学号、课程编号、成绩) 课程关系C(CNO,CNAME,TEACHER) (分别代表课程的编号、课程名、任课教师) 在关系SC中,查询学习课程号为′DB′,且成绩在60至90之间的学生学号的正确的 SQL命令是
A. SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE DETWEEN 60 AND 90
B. SELECT SNO FROM SC WHERE CNO=′DB′OR GRADE BETWEEN 60 AND 90
C. SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE>=60 AND 90
D. SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE<=60 AND GRADE>=90
TextOne of the advantages of taking notes is that it forces you to pay closer attention to the class lecture. If you listen (26) to a professor who is talking on and on for an hour or so, your mind will often (27) and your attention lessen. You arc sitting in class and listening, but that (28) you are doing; (29) when you listen actively you have to pay more careful and (30) attention to what (31) . This is because you are trying to (32) what you bear into an (33) , shortened written form. As a foreign student, you may find (34) very difficult to listen and write notes (35) at the same time. It is difficult (36) , but you will learn how to do (37) with practice. You (38) afraid you will forget what you are listening to (39) you are listening and writing at same time, but the studies of researchers (40) the value of note-taking in (41) lecture material have shown that learners remember (42) reproduced in some note form much better than lecture information they have listened to (43) down in note form. So doing two things at the same time is better than doing one thing. (44) . We do not say it is (45) ; we say it is better. 27().
A. wonder
B. widen
C. wander
D. concentrate
M: Have you made any plans to go away during semester break I’ve been thinking of skiing.W: I really haven’t had time to think about my vacation. I’ve been concentrating on getting ready for my exams, especially philosophy. But I’ll probably go to the beach.M: Why the beachW: Well, it would be nice to get away from this cold weather and just lie in the sun and relax after working so hard.M: It’s true that skiing does require work. And you have to get up early and wait in long lines for the chair lifts. Thanks. I think you help me make up my mind.W: Sure. Now maybe you can use your mind to think about something else, like your studies.M: Yeah, just as you said, I should focus more on study now, because the exams of various courses are approaching. If I cannot pass those exams smoothly, I will not have a good time in vacation.W: Absolutely! So now we should put the vacation aside temporarily and make good preparation for the exams. Do you want to go to the library with me nowM: Sure! Let’s go! What does the woman think the man should do().
A. Take a trip to the beach.
B. Go to a ski resort.
C. Study for his exams.
D. Think further about his vacation.
采用先进的程序设计技术不仅可以提高软件开发和维护的效率,而且可以提高______。