Questions

By searching for keywords that trigger your ad, you can rack up impressions without clicks, which may lower your Click-Through Rate, which may prevent your ad from appearing as often as it is eligible.

The alphabet 'Y' resembles same as the questioning word WHY in sounding.

Hence,  alphabet Y is a question.

Due process is the legal requirement that the state must respect all legal rights that are owed to a person.

Therefore, due process refers to the criminal justice system operating within the bounds of the law.

Agriculture would be a good example of a purely competitive industry.

Therefore the answer for What travels around the world but stays in one spot is STAMP or any other thing that acts as a stamp does.

Ex. the letter in the envelope etc...

Since, Several things have the possibility, but the word travel evokes that it would move. 

The combined gas law states that the ratio between the pressure-volume product and the temperature of a system remains constant.

Hence it depends on all the three Volume, Temperature & Pressure.