If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors?
As we know, scattering (散射) happens when light goes through the air. For the same media, if the wavelength (波长) is long, the scattering will be short. If the wavelength is short, then the scattering will be long.
Of all light we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.
Using the red light can help drivers in farther areas see the lights. It helps drivers slow down or stop in time. If drivers don’t see the red light until they are close, they may not be able to stop the car in time. An accident may happen. Red can also excite people. We can act more quickly when we see the color red.
In a word, red light helps drivers stop in time and help prevent accidents.
1.______ has the longest wavelength of all light we can see.
A. Red B. Green
C. Yellow D. Black
2.Red light travels farther on ______ days.
A. windy B. sunny
C. rainy D. cloudy
3.Red can make people act more quickly because ____________.
A. red can make people happier
B. the scattering of red is very short
C. the scattering of red is very long
D. red can make people more excited
4.The passage mainly tells us ____________.
A. why accidents happen
B. how the red light travels
C. why we use red traffic lights
D. how to stop in time at traffic lights
Besides calling 120, here is what you should do when no one is around to help.
| If you get lost, you may stay where you can be seen clearly and try your best to have a rest. In a wide open area, make a colorful cross out of rocks to show where you stay. |
| When you choke (噎住) at home, make a sudden hit against the back of the chair. If you can’t breathe after six tries, call 120. Leave the telephone open until help arrives. |
| If you get hurt, use your hand or a scarf, or any dry cloth you can find, and push down on the wound (伤口) until the blood stops running. Don’t put the cloth around your leg tightly, or you may lose your foot. |
| When a fire happens, you must move close to the floor. Cover your mouth and nose with a wet towel (毛巾), make you wet from head to foot if possible and find a safe place outside. |
1.If you get lost in a wide open area, you should ____________.
A. call out for help B. make a cross
C. phone the police D. draw a map
2.You move close to the floor in a fire to keep away from ____________.
A. smoke B. light C. noise D. rain
3.____________ can help to deal with a wound.
A. A wet towel B. A chair
C. A scarf D. Some rocks
完形填空
As a teenager, I am often asked what I am going to be in the future. A lawyer? A doctor? Or a scientist? No, my ideal career is to be a teacher. One of the for that is I want to be a teacher like Mr. Chen.
“Look! Do you know what it is? A-ha, it’s the ! And it will always move around the sun.” Mr. Chen said and pointed to his head. He then touched the nose and , “Can you tell me the name of this mountain? It is the highest mountain on Earth! What’s the of it? Yes, it’s 8844.43 metres…” I’ll never forget my first geography lesson. He was humorous that we all fell in love with his lessons . It’s Mr. Chen who opened the door of geography for us.
Generally speaking, most of the teachers are strict students and sometimes a little bit demanding（苛求的）, not so with Mr. Chen. He is a lighthouse, showing us the way to the treasure of knowledge. He is a friend and easy to get with, always encouraging us to speak out loud without 44 our shyness and other disadvantages. He is an example, volunteering his time to students and other teachers.
One day I happened to meet him in the hospital. Seeing the cut on his arm, I realized he was donating his . I was moved and was another lesson, a lesson of love and devotion.
Every time I see my globe（地球仪）, it would me of Mr. Chen. He is the most unforgettable teacher I have met and he will always be. Someday I hope I am to be a teacher like him.
Thank you, Mr Chen, thank you for making learning not a job but a joy.
Thank you for helping me to discover what I do best and to do it even
Thank you for understanding all of us and giving us the time and care each of us needs.
1.A. replies B. reasons C. rewards D. results
2.A. moon B. earth C. star D. sun
3.A. advised B. announced C. added D. answered
4.A. distance B. weight C. size D. height
5.A. very B. too C. really D. so
6.A. at present B. at once C. at times D. at first
7.A. with B. to C. in D. for
8.A. away B. together C. angry D. along
9.A. thinking B. caring C. considering D. supposing
10.A. money B. blood C. clothes D. time
11.A. taught B. given C. taken D. had
12.A. remember B. represent C. warn D. remind
13.A. just B. never C. ever D. yet
14.A. able B. about C. allowed D. availabe
15.A. well B. good C. better D. Best
—You won the first prize in the last Physics competition once again.
—___________. I made several mistakes.
A. Congratulations B. It doesn’t matter
C. Don’t mention it D. You must be joking
Much attention should be paid ____ the wild animals as many of them are dying out.
to protecting B. to protect C. protecting D. protect
Poor thing! Jack a fall while he on the ice. He got hurt badly.
A. was having; was skating B. was having; skated
C. had; was skating D. has had; was skating
