Answer:
A header file is a file with an extension. Which contains C function declarations and macro definitions to be shared between several source files. There are two types of header files: the files that the programmer writes and the files that come with your compiler.
D is the mode in witch only or mostly text is visible.<span />
The class clock type was designed to implement the time of day in a program. Certain applications, and additions to hours, minutes, and seconds, might require you to start at the time zone.