下图是异辛烷的球棍模型,则异辛烷的系统命名为( )
A.1,1,3,3-四甲基丁烷
B.2-甲基庚烷
C.2,4,4-三甲基戊烷
D.2,2,4-三甲基戊烷
答案:D
A common class of wire rope used for mooring is the 6x19 class. What does the 6 represent?()
A.Factor of safety
B.Number of wires per strand
C.Number of strands per wire rope
D.Number of wires in the core
电复律的绝对适应证是
A.阵发性室性心动过速B.心室颤动C.心房颤动D.预激综合征伴快速心房颤动E.心房扑动