初一的题目（科学和英语）科学：小明用100牛的水平方向的力去推放在水平面的桌子,课桌在30秒内匀速移动了6米.已知课桌的质量为30千克.求：（1）课桌受到的摩擦力为多大?（2）小明推课

　　初一的题目（科学和英语）

　　科学：

　　小明用100牛的水平方向的力去推放在水平面的桌子,课桌在30秒内匀速移动了6米.已知课桌的质量为30千克.求：

　　（1）课桌受到的摩擦力为多大?

　　（2）小明推课桌的速度为多少?

　　英语嘻……

　　ThomasEdisonwasoneofthegreatestinventorsintheworld.Withouthisinventors,peoplemaynothavelights,filmsandmanyotherthings.Butthisveryelevermanhadverylittlescholing.

　　Edisonbegantomakeatalkingmachinein1877.Atfirst,heusedpapertomakeasoud.Heworkedformonthsonthisidea.Atlasthefoundouthowtorecordaperson'svoide.Butthefirstmachinewasverysimpleandthevoicewasonesonthetalkingmachine.Thistimethevoicecouldbeplayedbackandthevoicewasalsoveryclear.AftertheWorldWarII,othersusedhismethods,andthencamethefirstmoderntaperecorder.Itismucheasiertorecord.HowgreatEdisonwas

　　1.Edison_________verylittleschoolingwhenhe___young.

　　2.Thefirsttalkingmachineheinvented__________veryslmpleandthevoice____________________________

　　3.Thefirstmoderntaperecorder_________invented________theWorldWarII