Is it okay to copy and paste a sentence written by someone else into your own paper and simply add quotation marks around it?

What does the excerpt tell about the narratos mental shift i suppose i shall have to get back behind the pattern when it comes night,and that is hard? @a.the narraor believes that the wallpaper is beatiful b.he believes that the woman in the wallpaper will attack him when he sleeps c.the narrator believes that he cant escape from the windws with the bars d.that the narrator was once behind the wallpaper