another:(of 3 or more) another (one) ; another two hours = two more hours 又两小时
both:(of 2) both of us (neither of us); on both sides of the road = on either side of the road
each:each/ every student; each of us = every one of us ( 不可说：every of us)
They each have a book.= Each of them has...( 不可说：They every have a book).
every:every/ each student;