1.  For instance, a professor making researches in the field of physics maybe does excellent research which may be of no connection with the applications and teach them to students well when he or she doesn't go outside to learn what the practicality is like.

2.  For instance, a professor making researches in the field of physics maybe does excellent research which may be of no connection with the applications and teach them to students well when he or she doesn't go outside to learn what the practicality is like.

3.  Firstly, you don't have to go outside your warm house and can buy almost everything, especially in terrible days.