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Regarding young people who don't know the date of the end of the pacific war:

> 中学校や高校の歴史の授業は、太平洋戦争を教える前に **終わってしまうこと** が多いため、知らない人が増えているのだと思います。  
>  I think the number of people who don't know (the date) is increasing
> because _there are many things that will finish_ before middle school and
> high school history classes teach about the war.

I can't make any sense out of the part in bold. What is coming to and end?
What does こと refer to?
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2017-08-13T18:50:21.757
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2017-08-13T20:26:31.573
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question
parsing reading-comprehension
Unusual meaning of 終わる or just a parsing failure?
Parse it like this:

  * 中学校や高校の歴史の授業は、: middle and high school lessons in history: TOPIC
  * 太平洋戦争を教える : teaching the pacific war
  * 前に : before
  * 終わってしまう : end
  * ことが多いため、: it often happens that CAUSE
  * 知らない人が増えている : people who don't know are increasing
  * のだと思います。: I think

Read to TOPIC, then read the CAUSE in reverse order, then the remainder in
reverse order.

  * Because middle and high school lessons in history often end before teaching the pacific war, I think people who don't know are increasing.

ことが多い : This is a very common expression for things (abstract こと things, not
もの concrete things) happening a lot.
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2017-08-13T19:20:24.373
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You're off to a good start. There are just a couple of things. I know you said
that this sentence was in a context of students not knowing the date for the
end of the Pacific War. However, just looking at this one sentence outside of
that context, I would construe it rather differently.

The core of the sentence is

> 知らない人が増えている  
>  There are _more and more people_ who are uninformed.

Here "more and more people" is my way of handling "人が増えている".

The speaker wants us to know that this is their opinion, so they add

> ...のだと思います  
>  I think it is the case that ...

Just putting these two parts together, we get

> 知らない人が増えているのだと思います  
>  I think it's the case that there are more and more people who are
> uninformed.

So, we could ask the question, "why does the speaker have this opinion?" Well,
they told us already, that's the part of the sentence that precedes ため.
Namely,

> 中学校や高校の歴史の授業は、太平洋戦争を教える前に終わってしまうことが多い

Here is where is seems you got a bit more stuck about what's happening in the
sentence. This portion of the sentence can be broken down into four parts.

> ことが多い  
>  [Something happens] a lot.

What happens a lot?

> [何か]が終わってしまう  
>  [something] _unfortunately_ comes to an end

I'm using "unfortunately" here to get across the idea communicated by てしまう. I
only know to do that because of the larger context of the meaning.

The something here is

> 中学校や高校の歴史の授業  
>  Middle school and high school history classes

Putting these three things together gives us

> 中学校や高校の歴史の授業が終わってしまことが多い  
>  Middle school and high school history classes unfortunately _frequently_
> come to an end

Notice that I use "frequently" to get across the idea of ことが多い.

Now the final part, why is this a concern? The context you were talking about
was regarding students not knowing certain dates. So, the final piece of the
puzzle is

> 太平洋戦争を教える前に  
>  before they teach about the Pacific War

So, putting this forth piece together with the three previous pieces, we get

> 中学校や高校の歴史の授業は、太平洋戦争を教える前に終わってしまうことが多い  
>  Middle school and high school history classes unforunately frequently come
> to an end before they teach about the Pacific War

Now putting it all together, you get

> I think that there are more and more people who are uninformed [about the
> Pacific War] because middle school and high school history classes
> unforunately frequently come to an end before the Pacific War gets taught**.

Technically, there's no passive construction in the sentence, but I'm just
trying to render the last part a bit more smoothly into English.
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2017-08-13T20:20:58.413
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