An article that denotes class of objects

[AlexAD]

Thank you all for keeping up the discussion.
The most important thing is that I've come to conclusion with the help of you fellows that both "The Undefinite" and "The Definite" articles will suit in this situation.
Thank you!

[Khosro]

Thank you all for keeping up the discussion.
The most important thing is that I've come to conclusion with the help of you fellows that both "The Undefinite" and "The Definite" articles will suit in this situation.
Thank you!

Perhaps, but What is your sentence? We are not just looking for a rule about the relationship between class and articles.

Please read fivejedjon's post No. 9 more carefully.

[Tdol]

Well, let's focus on the following sentence:
The giraffe is the tallest of all animals?

I've got that example from Murphy's book and it seems very unacustomed that they were a mistake there. The giraffe is a class (actually it is a subclass) of animals and attention is paid to that fact in the sentence.

Ok, what can we say then considering another sentence compared with previous one?

You enter the house by the street door.

Why wouldn't we say that we're speaking about a house like a class of buildings?

P.S. I didn't make those examples up I'm just trying to find out what kind of book I'm learning says lie.

I think that the potential ambiguity of You enter the house... makes it a very unlikely form- it is possible IMO, but just a bit tooo unclear. You'd need to be in a zoo looking at a giraffe among elephants for the same possible ambiguity. It's not incorrect, just better avoided if you want to get your point across clearly, and You enter a house/houses are better options.