definite article

Hi,

Do you think the follwing definite articles are placed due to the fact that the situations (or context) make it definte (or clear) and that's the reason why the articles are placed? Good enough reason? I saw this on online grammar exercise that quoted permission from Mother Jones Magazine. The content was noted as in "Cold Comfort" from Mother Jones Magazine by Michael Castleman.

(The previous sentences and paragraphes were spent talking about the loss of antibiotic effectiveness against common bacterial illnesses.)

Your brother catches a cold that turns into a sinus infection. Hs doctor treats him with antibiotics, but the bacteria are resistant to all of them. 

1. Why 'the bacteria' when bacteria haven't been discussed or noted all along? It is placed since it is 'definite' (or clear??) from context?

Then few sentences later it has this sentence:

Far-fetched? It's not. The antibiotics crisis is real.

2. Why 'the antibiotics crisis' with 'the'? The writing didn't seem to mention any explicit crisis but seemed to have been leading to that direction, so placing 'the' with 'crisis' seems reasonable?  

Anonymous

Why 'the bacteria' when bacteria haven't been discussed or noted all along?

They have been noted implicitly, though.  The word the triggers the reader to find something in the situation which makes the following noun refer to something definite.  You can often add a relative clause to make explicit the feature in the situation that defines the noun uniquely.

... but the bacteria (that caused the sinus infection) are resistant to ... 

Without the you have a generic statement which is out of place in the story. 

His doctor treats him with antibiotics, but (all) bacteria (in general) are resistant to all of them.

____________ 

Anonymous

The antibiotics crisis is real. ... Why 'the antibiotics crisis' with 'the'?

You only have two choices.  You must have the or an.  Are you arguing that an would make more sense?   

Think of a / an as meaning it-doesn't-matter-which.

His doctor treats him with antibiotics, but it-doesn't-matter-which bacteria are resistant to all of them.

Far-fetched? It's not. It-doesn't-matter-which antibiotics crisis is real.

The two statements above don't make sense. 

___________ 

Think of the as meaning you-know-which. 

His doctor treats him with antibiotics, but you-know-which bacteria are resistant to all of them.

Far-fetched? It's not. You-know-which antibiotics crisis is real.

Now these two make sense. 

___________ 

How you know which can be from words previously used in the narrative, but it doesn't have to be.  How you know which can be from your knowledge of the relationships in the real world.

I took a taxi yesterday.  Fortunately I had enough money to pay the driver.

"Why the driver?", you ask.  "Nothing about a driver has been mentioned previously.  How can I know what is meant by the driver?"  Answer:  You're smart enough to know that all taxis have drivers, so if I mention a taxi and then use the expression the driver, I can't mean anything more or less than the driver of that taxi.

----- 

Paula entered a restaurant.  She noticed that the door was broken.

Why the door?  Nobody said anything about a door previously in this story.  How do we know which door?

Because we're smart enough to know that entering a restaurant probably involves a door.  It must be the door of that restaurant. 

-----

A waitress gave her a menu, and she ordered the roast beef.

Why the roast beef.  We have to assume that "Roast Beef" was listed on the menu she was given, and she ordered the roast beef that was listed on that menu.

-----

I hope it's getting clearer for you.   

CJ