液化石油气能使石油产品溶化，其阀门填料应采用（）。 ["氯化氢","聚氯乙烯","聚四氟乙烯","石棉"]
Which WebSphere Commerce features require the Scheduler component to be running？（） ["Auctions","Database replication","E-mail notifications","Discounts","Marketing campaig"]
按照国家有关部门规定，建设项目设计概算应在（）阶段编制。 ["前期决策","初步设计","施工图设计","施工期间"]
简述金风1500机组安全链系统的组成?
什么是健康风险因素？心血管疾病中有哪些风险因素？
城市人口规模的制约因素有哪些？
