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