From Twitter:

(Choose the better style.)

1. ___is different in my province of Japan.
a. The taste of the soy sauce
b. The soy sauce's taste

2. ___ is where the fuel is kept in most airliners.
c. The wing of the plane
d. The plane's wing

Answers:

1. a
2. c

Explanation: Ownership or possession is the ability to "have" things, to "possess" them and to "keep" them; we usually show ownership in English by adding 's. Look:

Bob's skis
Lily's tablet
the president's stupid hair
the dude's bowling ball

the floor of the car
(a car can't own a floor.)

the wing of the plane
(a plane can't possess a wing.)

the roof of the house
(a house can't keep a roof.)

Traditionally we do not give the power of ownership to things, inanimate (non-animated/non-moving) objects, non-lifeforms. So--to indicate that something is a part of something else or belongs with it or is part of it, we use the (or a) and of.