What is the time/period in the book crispin by avi

Which sentence in this excerpt from the time machine suggest that the time travelled will later realize that his assumptions about future society are incorrect

When the telephone rings incessantly, what is it that the men want to have happen? they want the phone to be answered because it is jangling their nerves. they want mr. frank to go to the office and answer it because they are afraid it might be bad news. they want mr. frank to go to the office because they think it might be miep. they want mr frank to ignore the phone.

Why is it important to include a descriptive subject heading? it in sorting the topics. it the recipient see its importance. e-mail programs won’t allow e-mail to be sent without it. it keeps junk e-mail separate from important e-mail.