完形填空。 Now more and -more students have their own cellphones. Do you have one? If you I , you will know how useful they are. With one, you can call your parents or friends 2 you want. However, there are risks with cellphones. Sending messages is a good way 3 in touch with your friends. But you can also receive some spam messages(垃圾信息) 4 you receive a rude message, do not reply to it. If a message tells you 5 you have won a big prize, don't believe it. When someone you don't know calls you and asks you to go out, don't go. If you don't know how t0 6 these problems, ask your parents for help. Let them know who your friends are, and when and where you use your phone. 7 your parents' help, you won't have to worry about 8 unwanted(不需要) 'calls or messages. Some kids 9 a lot of time playing s and sending messages. They 10 do it in class. It's a waste of time and it's bad for your learning. Studies are always important. Turn off your cellphone and put it in your schoolbag before class. Don't play with it in class. ( )1. A. did ( )2. A. whenever ( )3. A. keeping ( )4. A. But ( )5. A. which ( )6. A. set up ( )7. A. On ( )8. A. getting ( )9. A. take ( )10.A. never B. doing B. whatever B. to keep B. If B. if B. come out B. After B. to get B. spend B. often C. do C. however C. kept C. Unless C. whether C. deal with C. In C. get C. pay C. hardly ever D. done D. wherever D. keep D. Since D. that D. do with D. With D. got D. cost D. even