当三相交流发电机的三个绕组接成星形时,若线电压uBC=380√2sin ωtV, 则相电压为下列式中的哪一个?()
A、20√2sin(ωt+90°)VC
暂无解析
StudentswanttokeeptheSelf-AccessCentrebecause____.
国际航协北京办事处成立于()。
Manypeoplebelievethatscientificresearchshouldbecarriedoutandcontrolledbythegovernmentratherthanprivatecompanies.Towhatextentdoyouagreeordisagree?
国际货运代理企业为货主提供服务时,应当遵循的基本原则有()。
Tobeginwith,"muzak"(音乐广播网)wasintendedsimplytocreateasoothing(安慰)atmosphere.Recently,however,it'secomebigbusiness—thanksinparttorecentresearch.Dr.RonaldMilliman,anAmericanmarketingexpert,hasshownthatmusiccanboostsalesorincreasefactoryroductionbyasmuchasathird.But,ithastobelightmusic.Afastonehasnoeffectatallonsales.Slowmusiccanincreasereceiptsby38%.Thisisprobablybecauseshoppersslowdownandhavemoreopportunitytospotitemstheyliketobuy.Yet,slowmusicisn'talwaysanswer.Dr.Millimanfound,forexample,thatinrestaurantsslowmusicmeantcustomerstooklongertoeattheirmeals,whichreducedoverallsales.Sorestaurantsownersmightbewelladvisedtoplayup-tempomusictokeepthecustomersmoving—unlessofcourse,theresultingindigestionleadstocomplaints!
练习:
1.Thereasonwhybackgroundmusicissopopularisthat______.
A.itcanhaveapowerfuleffectonthosewhohearit
B.itcanhelptocreateasoothingatmosphere
C.itcanboostsalesorincreasefactoryproductionerywhere
D.itcanmakecustomerseattheirmealsquickly
2.Backgroundmusicmeans________.
A.lightmusicthatcustomersenjoymostB.fastmusicthatmakespeoplemovefast
C.slowmusicthatcanmakecustomersenjoytheirmeals
D.themusicyouarelisteningtowhileyouaredoingomething
3.Restaurantownerscomplainaboutbackgroundmusicbecause______.
A.itresultsinindigestion
B.itincreasestheirsales
C.itkeepscustomersmoving
D.itdecreasestheirsales
4.Theword"up-tempomusic"probablymeans_____.
A.slowmusic
B.fastmusic
C.lightmusic
D.classicalmusic