单项选择题 某些物质受到光照射时，除吸收某种波长的光之外，还会发射出比原来吸收波长更长的光。当激发光停止照射时，发光过程几乎立即停止，这种光称为
未知题型 When the key is pressed, the 7-segment digital tube displays ’P’, and the LED is turned on. When the key is released, the 7-segment digital tube displays ’-’, and the LED is turned off. The key is connected to P3.2, as an interrupt 0 input.
单项选择题 氯气被液化是一个（）过程