To watch carefully in order to learn something. (observe/view)
Observe
One hundred percent, as much as possible. (among/completely)
completely
Essential in order for something else to happen (necessary/discovered)
necessary
To look at or see something (observe/view)
view
To send back from a surface (reach/reflect)
reflect
How large or small something is (among/size)
size
Thought of and made something new (invented/discovered)
invented
Arrive at a level, a place or an amount.(reach/necessary)
reach
Part of a group (Among/Completely)
Among
Became aware or learn about something (invented/discovered)
discovered