综合填空：

　　What do you usually use mobile phones for?Sending text messages for fun?Playing games?Well, mobile phone can do f　　1　　 more than that．D　　2　　 this year’s Asian tsunami(海啸)，mobile phones saved many l　　3　　．More than 10000 international phones were w　　4　　 when the tsunami hit．Police sent text messages to them and found more than 2000．But how?People f　　5　　 the signal and found out w　　6　　 the tourists were．So, how can s　　7　　 so small be so smart?Well, here’s how!When you turn the phone on, it tries to find a signal．This signal．This signal comes from the telephone network．

　　If you have a signal you can see it on the phone’s screen．Sometimes, if the signal is weak, i　　8　　 can be difficult to make a phone call．When the phone is finding a signal, it also sends a m　　9　　 to the telephone network．This message tells the station where the phone is．When you start to make a phone call, the telephone network tells telecommunication offices where you are．The office will find out who you’re calling then put you t　　10　　 to your friend!