Is Oxygen a waste made by cells?

When a person undergoes root canal treatment or another endodontic treatment: [select all that apply] a.) the inside of the tooth is carefully cleaned and disinfected. b.) air is forced into the canal to stop bleeding. c.) the inflamed/infected pulp is removed. d.) the inside of the tooth is filled and sealed with a rubber-like material called gutta-percha

You are traveling down the road and the hopd flies up- a. look out of the gap between hood and cowling b. look out the left window c. stop the car d. turn on your four-way flashers e. use stop signal given with arm 2. you are driving down a dark, country road and the headlights suddenly go out- pull off the side of the road and stop flash your break lights activate your four way flasher have scotty beam you up turn your parking lights on 3. you turn on a crowded street and the accelerator pedal sticks- turn ignition off shift to neutral apply the brakes reach down and pull pedal by hand use the of toe of your food to pull pedal up

What can evoke feelings of terror and panic