when we should use "entrance" and when "penetrate" ? f.e. sent.: we a well-known in America but now we want to ... the European market? (what's in the gap?)
You might like to look at each definition (at least on wikipedia) as they are close synonyms. You can both enter and penetrate the European market, though "penetrate" seems more aggressive (like a sword penetrates a body, while a person enters in a building).
