题目内容

下面关于隔离放大器,说法正确的是()

A. 光电隔离放大器前后可以有电的连接
B. 光电隔离放大器前后不能共用电源,地线也不能接在一起
C. 光电耦合器体积大、工艺复杂、成本高
D. 电磁耦合体积小、使用寿命长、工作范围宽

查看答案
更多问题

Which of the following items would be patentable?

A distinctive way to produce a new cloth material
B. A textbook
C. The theory of relativity
D. A method that has the potential to increase output of a certain crop

In most cases, how long does a copyright lastin China?

A. 50 years
B. 17 years
C. 70 years
D. The author's life plus 50 years

The apple which identifies Apple Computers is an example of a

A. trademark
B. service mark
C. patent
D. Copyrighted work

Which of the following are limitations to copyrights?

A. Fair use
B. Compulsory licenses
C. License agreement
D. All of the above
E. Both fair use and compulsory licenses

答案查题题库