在通常情况下,一般钢制容器对爆炸极限无明显影响
1、正确正确
暂无解析
遗传咨询中,具有垂直传递和终生性特征的是()
Theagriculturalrevolutioninthe19thcenturyinvolvedtwothings:theinventionoflabor-savingmachineryandthedeyelopmentofscientificagriculture.Labor-savingmachinerynaturallyappearedfirstwherelaborwasscarce.“InEurope,”saidThomasJefferson,“theobjectistomakethemostoftheirland,laborbeingabundant:hereitistomakethemostofourlabor,landbeingabundant.”ItwasinAmerica,therefore,thatthegreatadvancesin19thcenturyagriculturalmachineryfirstcame.
Attheopeningofthecentury,withtheexceptionofacrudeplowfarmerscouldhavecarriedpracicallyalloftheexistingagriculturalimplementsontheirbacks;by1860,mostofthemachineryinusetodayhadbeendesignedinanearlyform.Themostimportantoftheearlyinventionswastheironplow.Asearlyas1790CharlesNewboldofNewJerseyhadbeenworkingontheideaofacast-ironplowandspenthisentirefortuneinintrodueinghisinvention.Thefarmers,however,wouldhavenoneofit,claimingthattheironpoisonedthesoilandmadetheweedsgrow.Nevertheless,manypeopledevotedtheirattentiontotheplow,untilin1869JamesOliverofSouthBend,Indiana,turnedoutthefirstchilled-stillplow.?
1.Whatisthemaintopicofthepassage?
a.Theneedforagriculturaladvancestohelpfeedagrowingpopulation.
b.Thedevelopmentofsafermachinesdemandedbythelabormovement.
c.Machinerythatcontributedtotheagriculturalrevolution.
d.NewJerseyasaleaderintheagriculturalrevolution.
2.Theexpression“makethemostof”inLine4isclosestinmeaningtowhichofthefollowing?
a.getthebestyieldfrom
b.raisethepriceof
c.makefulluseof
d.earnalivingon
3.WhichofthefollowingcanbeinferredfromwhatThomasJeffersonsaid?
a.EuropewaschangingmorequicklythanAmerica.
b.EuropehadgreaterneedoffarmmachinerythanAmericadid.
c.Americawasfinallyrnningoutofgoodfarmland.
d.TherewasashortageofworkersonAmericanfarm.
4.Itcanbeinferredthatthewaord“here”inLine4refersto_____.a.Europe
b.America
c.NewJersey
d.Indiana
5.Whatpointistheautormakingbystatingthatfarmerscouldcarrynearlyalltheirtoolsontheirbacks?
a.Farmershadfewtoolsbeforetheagriculturalrevolution
b.Americansweretraditionallyself-reliant.
c.Lifeonthefarmwasextremelydifficult.
d.Newtoolsweredesignedtobeportable.
按计划免疫程序,小儿接种麻腮风减毒活疫苗的适宜年龄是()
下列属于高危儿的是()
5岁小儿,1个月来消瘦,乏力,低热。查体:颈部淋巴结肿大,肺部无啰音,肝肋下1cm,结核菌素试验(++)。胸片:右肺可见哑铃状双极影。诊断为()