21. Frank Enstein delivered his newspapers one evening. To deliver his newspapers, Frank traveled 3 blocks East, then 2 blocks North, then 3 blocks West, then, finally, 2 blocks South
What Frank's displacement? Hint: It may be helpful to draw this out.

in most common fires, oxygen is needed for an oxidation reaction to takes place. the combination of oxygen with any element as fuel can create fire and combustion will occur especially if wood, light materials and other combustible things are combine with oxygen.