两个不相等的实数m、n满足m2-4m=3,n2-4n=3,则m+n的值是( )

题型:选择题

问题:

两个不相等的实数m、n满足m2-4m=3,n2-4n=3,则m+n的值是(  )

A.4

B.3

C.-4

D.-3

考点:代数式的求值
题型:选择题

据《河南商报》报道,河南电视台都市频道23岁的女记者曹爱文,在一次采访落水少女的报道现场,曹爱文不是先驱采访,而是挺身而出,趴在女孩子身上做人工呼吸,她的这种责任来自[ ]

A.职业的要求    

B.道德原则    

C.分配的任务  

D.家长的命令

题型:选择题

肌电图检查静息时自发电位包括()

A.正锐波

B.纤颤电位

C.束颤电位

D.插入电位

E.终板电位

题型:选择题

焊接低、中碳钢和低合金钢构件时,当其受力情况复杂时,宜选用()。

A.与钢材强度相等的焊条

B.比钢材强度高一级的焊条

C.比钢材强度低一级的焊条

D.与钢材化学成分相同的焊条

题型:选择题

借新还旧,或者需通过其他融资方式偿还的贷款应至少分类为()

A、正常类

B、关注类

C、次级类

D、可疑类

题型:选择题

Many people are surprised when they find the Internet(因特网)was set up in the 1960s. At that time, computers were large and expensive. Computer networks(网络) didn’t work well. If one computer in the network broke down, then the whole network stopped. So a new network system (系统) had to be set up. It should be good enough to be used by many different computers. If a part of the network was not working, information could be sent through another part. In this way computer network system would keep on working all the time.
At first the Internet was only used by the government, but in the early 1970s,universities(大学) ,hospitals and banks were allowed(允许) to use it too. However, computers were still very expensive and the Internet was difficult to use. By the start of the 1990s, computers became cheaper and easier to use.
Today it is easy to get on-line(上网) and it is said that millions of people use the Internet every day. Sending e-mail is more and more popular among students.
The Internet has now become one of the most important parts of people’s life.

At first computer networks ______.

A. worked quite well
B. were very popular
C. went wrong easily

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