下列运算中,正确的是( ) A.2+3=23 B.(x+2y)2=x2+4y2 C.x

题型:选择题

问题:

下列运算中,正确的是(  )
A.2+
3
=2
3
B.(x+2y)2=x2+4y2
C.x8÷x4=x2D.
1
x+2
÷
1
x2-4
=x-2
考点:有理数除法完全平方公式分式的乘除实数的运算
题型:选择题

Mails, games, music, news, chat rooms and shopping! The Interent is part of our life today. It’s easy to get onto the Internet. The only thing we need to do is to use a modem(调制解调器) which is used for connecting a computer to a telephone line. The Internet is changing and growing all the time. More and more people have computers and use the Internet. Using the Internet means surfing the World Wide Web(That’s the “WWW” you always hear about). The Internet has a large number of websites(网站). They are the places where you go to get information and do things.

Where do these websites come from? They are made by web designers. What happens when you click on a word or a picture? You are sent to another page. It’s all because of the web designers. Web designers do a lot of work by using a computer programming(程序编制) language.

Is web design all about computer programming? No, it’s about making something new. Web designers must imagine a lot when they are making a website. It must look good and be fun to use. A big part of web design is art. They choose the best pictures and colors to make the website look good. They also write the things that you see on the website. An important part of their job is to share ideas with the website manager about how to design the website well.

小题1:More and more people are using the Internet because _____.

A.it’s easy and useful

B.it’s changing and growing

C.websites are designed quite well

D.people can design a computer小题2:Which of the following is WRONG?

A.“WWW” means “World Wide Web”.

B.There’re a few websites on the web.

C.The Internet has changed people’s lives.

D.We can do things like shopping on the Internet.小题3:It’s possible for us to change websites just by a click because of _____.

A.the modem’s help

B.the telephone line’s help

C.the web designers’ work

D.the website manager’s work小题4:The last paragraph is mainly about _____.

A.computer programming language

B.the web designers’ work

C.how to make a website

D.how to use the Internet

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下图中a~d表示连续分裂细胞的两个细胞周期,下列叙述不正确的是

[ ]

A.a和b为一个细胞周期

B.c段结束DNA含量增加一倍

C.遗传物质的平分一般发生在d段

D.b和c为一个细胞周期

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质量为m的小物块A,放在质量为M的木板B的左端,B在水平拉力的作用下沿水平地面匀速向右滑动,且A、B相对静止.某时刻撤去水平拉力,经过一段时间,B在地面上滑行了一段距离x,A在B上相对于B向右滑行了一段距离L(设木板B足够长)后A和B都停下.已知A、B间的动摩擦因数μ1,B与地面间的动摩擦因数μ2,μ1>μ2,求x的表达式.

题型:选择题

银卡VIP客户可享受的服务包括()

A.委托代办

B.预约办理

C.机场/火车站绿色通道

D.免保证金开通国际漫游(长途)

E.3G终端优先试用

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开始加油前,加油员再次与顾客确认所加品种.牌号并设置数量,然后从加油机上取下油枪,同时向顾客提示加油机已()。

A.开始加油

B.输入所加油品数量

C.回零

D.开始计数

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