单项选择题
When a p-n junction is reverse-biased，its junction resistance is（）.
A.high B.low C.determined by the components that are external to the device D.constantly changing
单项选择题 The piecewise linear model，equivalent circuit of the diode consists of（）.
单项选择题 The characteristic of an ideal diode are those of a switch that can conduct current（）.
单项选择题 Which of the following is not a commonly used semiconductor material’？（）
