题干

小明用遥控器控制电视机时,想知道遥控器发出的究竟是红外线还是激光.

(1)他将遥控不对着电视机而是对着旁边的墙,发现也可以控制电视机.于是,他认为遥控器发出的是激光.他是____ (对/不对)的,原因是激光和红外线都是光,都可以发生光的____ .

(2)设计一种能够区分激光和红外线的方法:____ .

(3)小红在研究光的反射定律的时候,想在白纸上具体去记录光路从而测量反射角和入射角的大小,他先确定入射点,画出反射面和法线,按下激光笔的开关就有了入射光线和反射光线,一松手(开关断开)光线又没有了.你有什么办法能够在白纸上记录出光路.____ .

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同类题4

阅读理解

Several days ago,Brenda had a car accident.As a result.one of her legs had to be cut off.She became quiet and didn't talk to anyone.

    "I wish I could bring her friends to visit her," Brenda's mother said to the nurse."It's just too long a bus trip.""Don't worry," the nurse smiled."I have a plan."

    Later that day, the nurse told Brenda it was moving day.Before Brenda could refuse,the nurse had taken her to another room filled with colourful flowers."Here's your new roommate,Annie,"the nurse told a dark-haired teenager(青少年)on the other bed.

    Annie smiled.After the nurse left.she hopped (单脚跳)out of her bed and sat at the other end of Brenda's.

    "I lost one of my legs from bone cancer (骨癌),"she said."What happened to yours?"Brenda was so surprised that she couldn't say a word."You're  ▲  ."Annie continued."You've still got your knee.They had to take mine."

    Annie hopped back to her bed."l'd like to talk with you,but my friends are coming any time now,so I have to get ready," Annie said when she reached up and took off her hair!Her head was completely bald(秃的).

"Oh,I forgot to tell you,the medicine they gave me to kill(杀死) the cancer also killed my hair,"Annie said.

    When Annie's friends came.she introduced Brenda to them all.Before long,Brenda started talking with Annie and her friends.They didn't make her feel like a freak (怪人) at all!By the time the nurse asked·the visitors to leave.Brenda feIt great.

    The girls talked into the night and shared their dreams with each other.When it was time to go to bed,Brenda said,"Good night,Annie.Can't wait till morning."

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