Add punctuation: Most of us spend many hours a day indoors and if you work in an office or in a shop this amounts to a significant num
A: Most of us spend many hours a day indoors, and if you work in an office or in a shop, this amounts to a significant num

Add punctuation: The ebook is sent via email within 24 hours of receiving your order
A: The e-book is sent via e-mail within 24 hours of receiving your order.

Add punctuation: That field is called a primary key
A:
That field is called a primary key,