下列关于索引结构的叙述中，哪一条是正确的?
A、一个文件上只能建立一个索引B
暂无解析
Theengineer______myfatherworksisabout50yearsold.
Countrylifeisbetterthancitylife________itoffersfreshairandnoiselessenvironment
Withthepublicationof(),TheodoreDreiserwaslaunchinghimselfuponalongcareerthatwouldultimatelymakehimoneofthemostsignificantAmericanwritersoftheschoollaterknownasliterarynaturalism.
Jameshasjustarrived,butIdidn’tknowhe________untilyesterday.
IonlycalledthepolicewhenI________everythingelse.
