Ob- and Per-: Do you stand against or do you stand by?

Ob- is a commonly used Latin prefix which mean against 

or in the way of. Think of "obstruct."

Per-, on the other hand, is a prefix which means to by, 

by means of, or through. Think of "perchance."

All English words with Latin roots have a literal Latin meaning 
and the current English usage. For example, to object 
has the literal Latin meaning to throw against. 
In English, we use it to mean disagree with.

Complete the attached to test your knowledge of these
two common Latin prefixes, their literal meanings,
and their most common English usages.