Last week, I bought an alarm system for about $ 450. It consisted of a control unit with three small units. I put the control unit in the sitting-room and fastened the other units by the front door, back door and living-room windows. The instructions told us to choose three numbers, so we chose 4, 9 and 1, the last three numbers of our telephone number.
Now I must explain how the alarm works:
l There is a power siren(警报器) in the control unit. It makes a very loud noise.
2 Each of the small units sends out beams or rays in different directions. If anything moves, it breaks a beam. This sends a signal to the control unit. The siren makes a noise which you can hear 50 meters away.
3. When we go to bed, I press the three buttons numbered 4, 9 and 1. Then we have 30 seconds to get out of the room before the alarm starts to work.
That night I slept soundly because I was sure that no burglar(夜贼) could get into our house. However, at about 2:10 a. m., I woke up and heard the siren. “There must be a burglar in the house,” Mary said. “What shall we do?”“I’ll go and see who’s there,” I said. “Stay here. Don’t make a noise.”I went downstairs quietly. When I reached the living-room, I switched on my torch and looked round the room. Then I turned the light on. I switched the siren off and searched the rooms downstairs. There was nothing wrong except that the back door was unlocked. I locked it, reset the alarm and went back to bed. About an hour later, the alarm started again. I jumped out of bed, fell over a chair in the dark and bumped into the bedroom door. Mary woke up and started hitting me with a torch. “Hey! Wait a minute!” I whispered. “It’s only me. I’m going downstairs to see what’s wrong.”I went down into the living-room and listened for a moment. The only sound I could hear was the siren. I turned on the light and then switched the siren off. As I did so, I glanced across at the curtains in front of the windows. I saw a house lizard (a kind of small animal) disappear behind the curtains.“Oh!” I said to myself. “That’s our burglar. ”When the lizard moved, it started the siren. I guessed that the alarm had been made in Europe, where there are no house lizards. Well. I won’t finish this story but if you want an alarm system free of charge, let me know. I’ll send you ours. We bought a dog this morning. It knows the difference between a lizard and a burglar.
小题1:The writer bought an alarm system to ________.
|A．make sure that he got up early every day|
|B．warn him when there were lizards in his house|
|C．frighten burglars and tell him that somebody had got into the house|
|D．make Mary feel safe to live in the large room|
小题2:The purpose of the three units was to________.
|A．send a message to the control unit and start the siren|
|B．sound their own sirens when the control unit told them so|
|C．check that the control unit worked properly all the time|
|D．give them enough light|
小题3:If the writer set the alarm and remained in the room for more than half a minute, _______.
|A．nothing would happen|
|B．the control unit would not work|
|C．the siren would make a noise|
|D．the dog would bark|
小题4:The purpose of the writer in writing the passage is to ________.
|A．tell us that the alarm system doesn’t work|
|B．tell us an interesting experience|
|C．show us how the alarm system works|
|D．make it clear that he wants to give away his alarm system|