Manybusinesspeoplechooseairtransportationbecauseitisfast,offersconvenience,anditi...Manybusinesspeoplechooseairtransportationbecauseitisfast,offersconvenience,anditisnotveryexpensive.这句话是平行结构错误.为什

　　Manybusinesspeoplechooseairtransportationbecauseitisfast,offersconvenience,anditi...

　　Manybusinesspeoplechooseairtransportationbecauseitisfast,offersconvenience,anditisnotveryexpensive.这句话是平行结构错误.为什么?谁能帮我具体分析下.