问题
选择题
下列说法正确的是[ ]
A．灯泡的灯丝断了再搭接起来，仍接到原电源上，其功率一定比原来的大
B．焦耳定律研究电能只转化为内能时的数量关系，用公式表示为Q=UIt
C．电热器的发热体是由电阻率大、熔点低的合金丝绕在绝缘材料上做成的
D．一段导体接在电路中，如果导体两端的电压增加一倍，则该导体每秒消耗的电能增加一倍
答案
答案：A
搜题请搜索小程序“爱下问搜题”
下列说法正确的是[ ]
A．灯泡的灯丝断了再搭接起来，仍接到原电源上，其功率一定比原来的大
B．焦耳定律研究电能只转化为内能时的数量关系，用公式表示为Q=UIt
C．电热器的发热体是由电阻率大、熔点低的合金丝绕在绝缘材料上做成的
D．一段导体接在电路中，如果导体两端的电压增加一倍，则该导体每秒消耗的电能增加一倍
答案：A
Passage Three
| There’s a great story about an old Finnish woman who, without quite realizing it, was using her cell-phone to access the Internet and track her city’s public transit system. When asked why she used the wireless Internet so frequently, she replied, "What are you talking about I don’t know anything about this wireless Internet stuff, I just know the bus is here." Regardless of whether you want to admit it, a lot of us are like that old Finnish woman. When it comes to new mobile applications, many of us do not realize the capability and power that we hold, literally, in our hands. What we’re looking at today is the mobile Internet in its infancy. Now that using the Inter- net from home or work has saturated much of society, the next logical step is to be able to use the Net when you’re away from your desktop or laptop. Speech recognition is one way to do this, and there are a number of services, collectively called the "voice Web", that will make this possible. All you do is use a phone or wireless device to call a phone number, and speak commands to an intuitive system. It will then give you the information you’re seeking, using either a synthesized voice or an audio file. In the United States and Europe, the hot technology for wireless devices is called WAP (Wireless Application Protocol), which is being considered as the world standard．WAP is supported by major phone companies including Nokia, Motorola and Ericsson, and is simply a means of transmitting information, much like HTML is a means of communicating on the Internet. Currently, wireless Internet connections may give you news, sports scores, stock quotes, and the weather if you’re lucky. But if you’ve ever used this technology, you know it’s slow, costly and doesn’t seem worth the time and effort, if it works at all. "The mobile Internet was never designed to take over surfing the Web from a computer," explains Cherie Gary, spokes woman at Nokia. All of this technology points to easier living. Perhaps you’ll need to find a restaurant for an occasional business meeting. You’ll press a button on your mobile phone, and access the Internet to pull up a list of great restaurants in your immediate area．You’ll hit another button, say a few words into tile handset and you’ve got a reservation for four. |
We can infer from the text that mobile Internet is different from the previous Internet in that mobile Internet______.
A．can be accessed by desktop
B．has no need of wire appliance
C．can be used to book the table for the user
D．has Speech recognition system