prim and proper (appropriate )

　　Hit the book:

　　Edge

　　Entrapment

　　Shut-off button

　　Secure

　　Unaware of

　　Be prone to

　　Mitten

　　Shoelace

　　Drawstring

　　Complex

　　Avoid the Steps' Edges

　　You should avoid the edges of an escalator's steps when riding one as possible entrapment may occur. Every escalator is designed to show the edge where you may be entrapped. The yellow lines in the sides of the escalator steps show the place where you should put your feet to avoid any entrapments.