阅读理解。 Talking on a mobile phone is expensive, so a lot of people send text messages. Text messages are much cheaper by making the words shorter. You can do this by taking out 'unimportant' letters in the words and using numbers instead of words (2=to, 3=free, 4 = for, 8 = ate, so, etc. ). You can also keep a way from using punctuation. Here is an example: Do u wnt 2 g 2 th cnma tnit? (Do you want go to the cinema tonight?) What do you think these text messages mean? Whr hv U bn? Iv bn wing hrs fr a cll. Im hm nw, why nt gv me a cll. I gt a txt mssge frm my frnd. Shes hvng a prty on Strdy. Mobile phone users have developed a group of symbols to show how they feel. They are called emoticons, and there are some examples below. To read an emoticon, you have to look at it sideways. For example, if you say something in a text message that is a joke, you can follow it with a smiling face. Like this : Why didt you call me? I'm so sad.－ (Here are some others. Can you think of text messages where you could use them? -) laughing, -( sad,  -< really sad,  -o shocked,  -v shouting,  | . | asleep,  8－| , surprised,  //-o  bored. 1. Why are text messages popular? A. Because they are expensive. B. Because they are cheap. C. Because they are hard to write. D. Because they are not important. 2. The first paragraph tells us that we can make the text messages shorter in _______ways. A. one B. two C. three D. four 3. What does this text message ' Do U wnt 2 cks?' mean? It means_______. A. Do you want to come? B. Do you wear two caps? C. Do you want two cakes? D. Do you go home early? 4. Why do people use emoticons? A. Because they can show how the users feel. B. Because the symbols are beautiful. C. Because the text messages are short. D. Because the users can't make the words shorter. 5. If you want to say someone is happy,  you could use the symbol ' ___ ' in the text message. A. -) B. -( C. -v D. |·|