TWO QUESTIONS: o2 Sensors and Dash

Question #1 - Ok. I have a 98 prelude base. Exactly how many o2 sensors are there and where are their locations on the 98 prelude. Are they easy to access? Also, how can you check if theyre still good or not?

Question #2 - A part of my dash kit started to peel off a little bit. What is used to stick the dash kits on? Im thinking the kit must come with adhesive already on it. If so, can I use something as a substitute?