关于leverage的用法问题
Ithasbeenabletoleverageitsrelationshiptoitsparentcompany,ChinaGoldenDragonMobileLimited(CGDM),toensurebeingabletoofferthebestratesbetweenHongKongandthemainlandandtolaunchnewproductsaheadofitscompetitors.
这一句中的leverageitsrelationshiptoitsparentcompany是什么意思?
还有里面的offerthebestrates中的rate是什么意思