While executing a command, the shell: a. Runs a shell script. b. Executes it in the same process as the shell. c. Creates a child shell to execute it. d. loads a special program to take care of the execution.

c. Creates a child shell to execute it.

Explanation: For commands to be executed by the shell, it runs/lainches a subshell also known as a child shell to execute it (opens the file, interprets it one line at a time). This child shell is a separate instance of the command processor and helps in running batches of commands simultaneously. On completion of each command, the child shell passes exit status to the parent shell which displays the result to the user while waiting for more commands.

answer: a. the kind of population living in your neighbourhood.

the census explorer data tool by the us census bureau allows the user to zoom in on any neighbourhood within the united states and find the kind of people residing in that by race and age.  

the tool needs to needs to be used twice – once in order to find what type of people reside in a neighbourhood, and then to see the age groups of the people in the same neighbourhood.