Internal Rate of Return内部收益率 Interest Rate Risk利率风险 Industrial Research Rocket工业研究火箭 Ionizing Radiations Regulations电离辐射的规定 Interim Research Review临时研究评论 Ionising Radiations RegulationsIonising辐射的规定 Institute of Resource Recovery学院的资源回收 Interference Reduction Ratio干扰减薄率 Internet Routing Registry网络路由注册 Individual Ready Reserve个人准备预订 Integrated Radio Room综合广播的房间 Information Request Response信息请求的响应 Image Rejection Ratio镜频抗拒比 Irregularadj. 不规则的, 不整齐的, 不合法的 Integral Rocket Engine火箭引擎