（）封合时，遇有分歧电缆的一端小对数电缆应在大对数电缆的下方。
参考答案：热缩管
A distribution of returns that has a greater percentage of small deviations from the mean and a greater percentage of large deviations from the mean compared to a normal distribution:（）
A. is positively skewed.
B. has positive excess kurtosis.
C. is negatively skewed.
短路电流产生的效应主要有（）。
A.热效应
B.磁效应
C.静电效应
D.电动力效应
