c. is written in front of a date or number to indicate that it is approximate. c. is an abbreviation for 'circa'.
the museum's re-creation of a New York dining room (c. 1825–35)
该博物馆对纽约一家餐厅(约1825年至1835年)的重建。
C or c is used as an abbreviation for words beginning with c, such as 'copyright' or 'Celsius'.
Heat the oven to 180°C.
把烤箱加热至摄氏180度。
C's, c's
C is the third letter of the English alphabet.
In music, C is the first note in the scale of C major.
If you get a C as a mark for a piece of work or in an exam, your work is average.