That depends on the sentence.
Does your brother enjoy fishing?
Do your parents enjoy fishing?
A skateboard should be used by pushing hard on the ground.
yes they should be used in class
it should not be used in any country
Pickles should not be only used on sandwiches.
it should be used for the care of your screen from harmful uv rays
no they should not
If a drug has expired, it is in a condition and should not be used.
the, an, a when these articles be used
it should be used when someone is ether sick or has an injury which is bleeding
Signposts should be used as often as possible where necessary.
yes it should be used in all netball games
Face book should be used as it is the most efficient way to communicate and it is the fastest.