聚乙烯混合物(粒状;含有少量作为增量性填充剂的碳酸钙)
参考答案:31 (3901.9090)
Classification is a useful ______ to the organization of knowledge in any field.
A.means
B.approach
C.mode
D.manner
根据《低压配电设计规范》,起重行车上方的裸导体至起重行车平台铺板的净距不应小于()
A.2.3m
B.2.4m
C.2.5m
D.2.6m