You should use "they do" with plural subjects, such as "they do their homework," and "does" with singular subjects, like "she does her chores."
The complete verb in the sentence is "should use."
You should use the blue key, not the yellow.
The auditor should use professional judgment in planning and performing all audits
we should minimize the use of fossil fuels and we should use carpools as well as as drive at a moderate speed. we should try to reduce the use of these fossil fuels that might help us in our future & we should use these fossil fuels carefully.
Yeah, that is fine.
You should use "are".
You should use did.
you should use meters
You should use your treadmill on a regular basis. You should use it every day if possible. You should use the treadmill for twenty to thirty minutes.
you should use you all
Why should you improve your ability to use the library?
There are number of different kinds of gas you should use. The gas you should use depends on the situation.
You should not. You should use centimetres.
we should use had if the sentence is in past tence
if we made mistake
you should use spagetti and sauce