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在“探究影响滑动摩擦力大小的因素”实验中,某同学按照如图所示的甲、乙、丙三种情况进行实验,其中A、B、C为同一木块,D为重物,甲和乙两图中的木板接触面相同,丙图为较粗糙的木板接触面.

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    We use the Internet for many things: business, shopping, writing letters, talking to people, finding information, and so on. In recent years, a new kind of English has grown on the Internet. There's no real word for it yet, so we'll call it e-talk. People don't like typing too much. To save time, they turn phrases (短语) into a few letters called acronyms(首字母缩略词). Acronyms are often used in chat rooms.
Some of them are:
BTW(by the way)     BRB (be right back)
LOL (laughing out loud) IMO (in my opinion)
People also use many abbreviations. They are shortened forms of words. Some common abbreviations are:
info (information)    puter (computer)    pic (picture)      sec (second)
We usually don’t see people when we communicate on the Net, so people have new ways to show feelings. Most people use their keyboards to draw “feeling”, such as:
: ) (happy)     :-( (sad) ;    : P (joking)   : O (surprised)
These days, many forums have picture feelings. For example:
happy          sad         angry        cool
There are even whole new words, like ‘newbie’ (someone who is new on a chat board or forum). When you write something bad about someone else, it’s called ‘flaming’ the person.
It takes time to get used to e-talk. Also, different groups in the Net have their own special ways of communicating. Newbies sometimes have to ask other people what they mean. As the Internet grows, e-talk will continue to grow and change.