?When a task requires ____ access, the User Account Control feature might prompt you to authorize the task.

An abstract class will:

a. Have all zero function pointers in its vtable. b. Have at least one zero function pointer in its vtable. c. Share a vtable with a derived class. d. Have fewer zero function pointers in its vtable than concrete classes have.

When you use the redirect output symbol (>) on a command line, the shell creates the output file immediately, before the command is executed. Dem- onstrate that this is true.

$ ls aaa ls: aaa: No such file or directory $ ls xxxxx > aaa ls: xxxxx: No such file or directory $ ls aaa aaa