The temperature of a certain day in Beijing

Analysis: The temperature in Beijing at night is 5℃ lower than 3℃ above zero at noon, which means that the temperature at night is 3℃-5℃, and the calculation formula can be listed accordingly.

3-5=-2.

So choose C.

Comments: The practical application of rational number operation is a common problem in senior high school entrance examination, and the key to its answer is to list the formulas correctly according to the meaning of the questions.