Before the elevator was invented in the late 1800s,buildings were much smaller and lower,as people did not want to walk up and down stairs all day.With the invention of the elevator came high-rise buildings and _ . Some people find elevators make them a little uncomfortable because there are many people all standing close in a small room.It is best just to relax and enjoy the ride. When the elevator doors open,stand aside and let everyone out before you try to get in.Even if you are in a hurry,it's impolite to push someone so that you can get into an elevator. Don't stare at people or stand too close.Try to keep your eyes looking ahead or you could make others feel nervous or uncomfortable. If you have to move past people to get out of the elevator,say"Excuse me,please"or"I'm sorry"rather than just push them out of the way.Others will think you're welcome if you show some politeness. If you are standing close to the buttons ,ask others what floors they are going to and press the buttons for them.This is considered to be polite. In case of emergency ,follow the instructions written inside the elevator and try to keep others calm. The elevator was invented  _  .
in 1800 in 1899 in the 18th century in the 19th century