问题 选择题

下列等式成立的是(  )

A.log2(3÷5)=log23-log25

B.log2(-10)2=2log2(-10)

C.log2(3+5)=log23•log25

D.log2(-5)3=-log253

答案

利用对数运算律,logmab=logma+logmb,可判断A正确

∵对数的真数大于0,∴2log2(-10)无意义,B错误

log2(3+5)=log28=3≠log23•log25,C错误

log2(-5)3无意义,D错误

故选A

阅读理解

Online Degrees

Today, you can earn a degree from a major university without ever having sat in one of their classrooms. Many colleges and universities are offering online courses and degree programs now.

Online Learning Programs

With a computer and an Internet connection, you can earn a degree from home, work, or anywhere else for that matter. Online degree programs follow much the same routines as traditional learning, with a few twists. There are lectures, but they won't be in person. There are assignments (作业) , but you won't hand them to your instructor. In most situations, you are free to "go to class" when it fits your"schedule. If you get a phone call during class, you don't have to miss anything. If you get sick, you don't have to ask for someone's notes, and you just visit the lecture later.

You'll communicate with your instructor by e-mail, chat room and instant messaging. Your  classroom will live in a special software program. Contrary to popular belief, you will have close  contact with other students and the instructor.

Evaluating the Program

There are a lot of questions to ask before you make your selection, such as:

How do students interact with each other?

★Online programs can use chat rooms, instant messaging, teleconferencing, and video conferencing to communicate. The key is to find a program that has this interaction built into it and even requires it.

★What kind of reputation does the school have?

It may seem simple-a good school will have a good online program. This reputation,however, may not be as straightforward as you think. It's not uncommon for a great school to have a weak program or two. So you'd better look at the overall quality of the school and make a judgment.

The Employers' View

As more and more employees get online degrees and use them in the workforce(职场) ,  hiring managers will begin to feel more secure about the quality of education these people have.

小题1:In which way is online education special?

A.If you get sick, you'll miss the lecture.

B.There are lectures, but you don't need to meet the lecturers.

C.If you get a phone call during class, you will miss something.

D.There are assignments, and you must hand them to your instructor.小题2:What is the most important part of online communication?

A.To use e-mails.

B.To look for a program with interaction.

C.To use chat rooms and instant messaging.

D.To use teleconferencing and video conferencing.小题3:For whom is the passage probably written?

A.College students.

B.Hiring managers.

C.Adult students.

D.High school students.

填空题