Studying in a public place like a station or bus is the worst. And studying in a library or home is the best. studying in a bus or station is worst because there are, at most times, noisy people around. The more unnecessary noise the less focused you are. And studying at home or a library is way better. The library is quiet so you wouldn't have to worry about not concentrating; being at home may be better because the familiar surroundings keep you comfortable.
