单项选择题

建筑钢材Q235级钢筋的设计受拉强度值2100kg/m㎡是根据以下哪种强度确定的?( )

A.弹性极限强度
B.屈服强度
C.抗拉强度
D.破坏强度
相关考题

E-mail or electronic mail, is considered as the modern ...


单项选择题E-mail or electronic mail, is considered as the modern communication in the new age. It is carried out in computers all over the world by millions of users. In this invisible world as many peo-ple call it, the users can send and receive letters to and from every coruer of the earth. They share thoughts with pen pals (笔友 ) in New Zealand, ask strangers in Bombay ( 孟买) questions, debate with businessman in Manhattan. All of these are just happening in computers as fast as the travelling of the light, no writing and speaking, no paper and stamps are necessary.
E-mail is a pipeline to thousands of experts on everything;it is a means of meeting people with similar interests or problems. But it is not a live talk--a real conversation like those in telephones.
E-mailers compose letters at leisure on their computers, then send them by phone line to an on-line service, and then they go forward to the right place. A response can be back within hours, depending on how often the recipient(接受者) checks in. A vast global networks of on-line services for E-mail has been built. A lot of people are regularly using this service in the USA. People believe that E-mail, the computerized exchange, would create friendship and business developments, and would change people′s life in the world.
Which of the following expression is not for E-mail?

A.Communicationinnewage
B.Invisibleworld
C.Alivetalk
D.Computerizedexchange