What two bash environment variables represent the current working directory, and the absolute pathname of the current shell, respectively?

PWD = current working directory. BASH = Full path name used to execute the current instance of bash. Nothing much to say here. No thinking, or logic needed. You simply need to know how to access the manual pages or other reference works for your command shell. You may wish to familiarize yourself with the "man" command. At the command line, type: man man And read what comes up. If the "man" command isn't installed on your system, please install it if you have the ability, or ask your instructor why it isn't installed.

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.