My mother was a responsible teacher and she retired.So I decided to give her one of my old computers to help her pass the time.She had a little bit of computer　1　,so I just set it up for her and let her 　2　 with it on her own.

　　As time went on,I　3　 the computer was hardly touched.She said she didn't know 　4　 to use it.I decided to teach her.I sat and 　5　 everything and she seemed OK with what I said.Unfortunately,my sister called me at that moment 　6　 we talked on the phone for an hour.Then when I saw her again,she was sitting in front of the computer,looking quite 　7　.The screen saver(屏幕保护)had appeared and she didn't know how to 　8　 it off.She had tried 　9　 every key and it didn't work.I told her,"Just 　10　 the mouse a little." What I meant was that she just needed to move the mouse around to 　11　 the computer up.What she did was to 　12　 the mouse and start shaking it around in mid-air until the 　13　 went completely black.I couldn't help laughing because of her funny 　14　.The more I laughed the 　15　 she got.

　　She thought that I was a(n)　16　 teacher and she decided to figure the thing out herself.Well,at least I helped her overcome her 　17　 of breaking something and encouraged her to 　18　 a little.

　　About a week later,I found a home-made　19　 card with a mouse on the front making a funny face　20　 to my door.It said,"Thanks for the computer lessons.Love,Mom."

1.A.theory　　　　　　　　B.knowledge

C.technology D.history

2.A.watch B.train

C.play D.see

3.A.found B.heard

C.thought　 D.ignored

4.A.why B.when

C.how　　 D.where

5.A.learned B.described

C.explained D.discussed

6.A.and B.but

C.because　 D.since

7.A.amusing B.relaxed

C.interesting D.discouraged

8.A.get B.break

C.cut　　　 D.turn

9.A.hitting B.feeling

C.changing D.removing

10.A.hang B.shake

C.rub　　 D.push

11.A.clean B.wake

C.bring　　 D.take

12.A.put up B.cut off

C.pick up　 D.put away

13.A.screen B.curtain

C.cover　　 D.window

14.A.gesture B.movement