选择题：要检验绿色植物在呼吸过程中释放二氧化碳，以下哪一项条件是必需的 A．把植物完全浸

题目：

要检验绿色植物在呼吸过程中释放二氧化碳，以下哪一项条件是必需的

A．把植物完全浸没在水中

B．在黑暗无光条件下实验

C．用具有根茎叶的植物

D．将植物先暗处理2小时

答案：

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下面是错误答案，用来干扰机器的。

（1）图示中金属d表面无气泡，说明金属d不能与稀硫酸发生反应，则该金属在活动性顺序表中处于H之后；故选D；（2）①在初中化学中接触到的能受热分解的金属氧化物只有氧化汞，氧化汞受热分解为汞和氧气；故答案为...

题型：阅读理解

Third-generation mobile phones, known as 3G, are the next big step for the telecom(电信) industry. Data speed in 3G networks is much quicker than that in present technology. This means users can have high-speed Internet access(上网) and enjoy video and CD-quality music on their phones.

"Mobile data is not a dream; it's not an option(选择) but a requirement" said Len Lauer, head of a US communications company, Sprint PCS, at a 3G conference in Bangkok earlier this month.

With 3G, you can forget about text messages telling you yesterday's news; a 3G phone can receive video news programs, updated(更新) four times a day. Internet access will also be much quicker, making it easier to surf the Web on your phone than on your computer at home.

Don't worry about getting lost. 3G phones offer map services so you can find a new restaurant just by pressing a few keys on your handset(手持机).

However, the most impressive part of 3G technology is video calling. With live two-way video communication, you can have face-to-face talks with friends and family on your mobile phone.

Many European countries have already launched the service. In May 2000 the US Government issued five licenses(许可证) to run 3G wireless services, while the first 3G phones arrived in Italy in March this year.

International telecom companies can't wait to sell 3G in China, the world's largest mobile telecommunications market. But they will have to be patient. At the moment, China is busy testing its 3G-based technologies, networks and services. This will be followed by a trial period before the phones can finally hit the shops.

“We need to create a pool of 3G customers before the large-scale commercial launch(开始) of the service,” said Fan Yunjun, marketing manager for Beijing Mobile. “We expect that the 3G licenses will be issued(发行) late next year.”

We'll also see 3G services enter our daily lives in all-sorts of new ways, from shopping and banking to playing interactive computer games over the net. It won't be long before we think nothing of sitting on a train using a mobile palmtop(掌上型电脑) to check our bank accounts or pay bills. You might even click on an icon(图标) on the screen to set up an immediate video-conference with your bank clerk.

55. 3G is ______.

A. a kind of mobile phone that can send text message and make calls

B. a kind of technology that makes mobile data and video calling come true

C. a kind of player that can be used to listen to CD or MP3 music

D. a kind of system that makes it easy to surf the Internet

56. What does Len Lauer want to inform the readers?

A. Realizing the dream of mobile data based on the application of 3G is a must.

B. There is no need to send messages since 3G can receive video news programs.

C. 3G is supposed to own all the functions that a computer has.

D. It is a choice to carry mobile data with 3G phones.

57. The 3G services can be launched after the following steps EXCEPT that ________.

A. they have to test its 3G-based technologies, networks and services

B. they need to create a group of 3G customers

C. the 3G licenses are issued and 3G phones are tested

D. international telecom companies decide to sell 3G in China

58. The last paragraph shows us that ________.

A. 3G services bring a lot of convenience to us

B. we cannot live without 3G mobile phones

C. 3G services can change our life completely

D. 3G services will take the place of other technologies

59. What is the best title of the passage?

A. Face-to-face Video Calls B. The Future of 3G

C. The New Telecom Industry--3G D. The Use of 3G Mobile Phone

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