刘晶家有一个12波段的收音机，其中的一个波段频率是7.5MHz～8.0MHz，则该波段的波长范围是多少？（电磁波的速度为

解题思路：李明的体重是35.5千克，刘晶的体重是李明的1.2倍，根据乘法的意义，刘晶的体重是35.5×1.2千克，又刘晶比张华轻3.2千克，则张华重35.5×1.2+3.2=39.4千克．

35.5×1.2+3.2
=42.6+3.2
=45.8（kg）
答：张华重45.8千克．

点评：
本题考点： 整数、小数复合应用题．

考点点评： 首先根据乘法的意义求出刘晶的体重是完成本题的关键．

To:The heads of departments
From:Liu Jing (Office director)
Date:July 8,2006
Subject:Annual Report and general manager of the personnel arrangements for the period abroad
1:Reminded the department heads ,I level personnel report to be submitted to give me the Ministry of Personnel on the July 30 ,if there are some diffierences ,please tell me.
2:The general manager will be held July 10 visit to Europe for business.So meeting July 12 .All events must report to the General Manager on July 9
虽然是电脑翻译的,但做了下改动,看了看比较准确

To:The heads of departments
from:Liu Jing (Office)
Date:July 8,2006
Subject:Annual Report and general manager of the personnel arrangements for the period abroad
1:reminded the department heads pay attention,I level personnel report to be submitted at the July 30 give me the Ministry of Personnel,if any difficulties please let us know.
2:The general manager will be held July 10 visit to Europe for business.So July 12 meeting canceled,all events must be July 9 to report to the General Manager.

解题思路：已知频率的范围，则可由波速、波长和频率的关系求得波长的范围．

由C=λf得：
λ₁=
c
f1=
3×108m/s
7.5×106Hz=40m
λ₂=
c
f2＝
3×108m/s
8.0×106Hz＝37.5m
故该波段的波长范围为37.5m～40m
答：该波段的波长范围为37.5m～40m．

点评：
本题考点： 波速、波长和频率的关系．

考点点评： 本题考查波速波长和频率的关系，属公式的简单应用．

λ ₁ =c/f ₁ =(3×10 ⁸ m/s)/(7.5×10 ⁶ Hz)=40m
λ ₂ =c/f ₂ =(3×10 ⁸ m/s)/(8.0×10 ⁶ Hz)=37.5m

To; the department heads
From:Liu Jing (Office)
Date:July 8,2006
Subject:Annual Report and general manager of the personnel arrangements for the period abroad
1,heads of departments are reminded that people's attention,this year's staff report must be in before the July 30 advance to the Ministry of Personnel,if this difficult situation
2.General Manager will be held July 10 visit to Europe to carry out business activities,the July 12 meeting canceled,if the need to July 9 to report to the Manager.

Hello, everyone!
I am very glad to tell all of you about myself. My name’s Liu Jing. I’m from Changchun, Jilin. I have some hobbies, such as going hiking and drawing pictures. I go hiking once a week. I’m good at drawing and draw every day. I’m outgoing. I like talking to other people. I want to be a scientist when I grow up. I feel lucky to join you. I hope to make friends with you and improve my English. I also hope we will have a good time.
That’s all. Thank you!

For Managers of all department
From Liu Jing (Office Leader)
Date 8/7/2006
Subject：
Annual HR report and the arragement when General Manager go abroad
1 Remind managers of all departments that the annual HR report should be handed to HR department before 30 July.If there is any difficulties,please inform me in time.
2.The General Manager will take a visit to Europe at 7 October for business activities.Therefore,the conference supposed to be held on 12 July is concealed.And all the important issues should be reported to General Manager before 9 July.
应该会比较专业,因为我是学商务英语的~

解题思路：已知频率的范围，则可由波速、波长和频率的关系求得波长的范围．

由C=λf得：
λ₁=
c
f1=
3×108m/s
7.5×106Hz=40m
λ₂=
c
f2＝
3×108m/s
8.0×106Hz＝37.5m
故该波段的波长范围为37.5m～40m
答：该波段的波长范围为37.5m～40m．

点评：
本题考点： 波速、波长和频率的关系．

考点点评： 本题考查波速波长和频率的关系，属公式的简单应用．