In the year 1846-48
Hello, please help me 
In the year 1846-48, Austrian Ida Pfeiffer went round...
Should I read -In the year eighteen forty-six to forty-eight ?
My student book says like this:
1846-48 Austrian Ida Pfeiffer went round the world alone.
9 Answers
It's more than one year, so I would write it, "In the years 1846 - 1848". If I were speaking I would say, "In the years eighteen forty-six to eighteen forty-eight".
But if it's just a timeline or outline, your book looks right.
I would say between 1846 and (18)48
I'd read it (aloud) like this :
Between eighteen forty-six and eighteen forty-eight the Austrian Ida Pfeiffer went round the world alone.
Or 'in the years', as Kevin and Marianne said - but I prefer 'between', personally.
Between eighteen forty-six and eighteen forty-eight
There is room for ambiguity with this expression. It can be interpreted to mean at some time within that period she circumnavigated (the world) although the actual trip took no more than, say, eighty days or it can mean that the duration of the trip was two years. The other formulations offered also are somewhat ambiguous (but less so). "during 1846-48" she traveled/was traveling" would be clearer.
I would go with using "between". However, if you are studying British English, how they speak varies slightly from American English. For example, you quote the book as saying "Austrian Ida Pfeiffer went round the world alone.", which sounds a little strange to me, because I would use the word "around", as opposed to "round".
One could also say...
From eighteen forty-six to eighteen forty-eight....
What Kevin says.
However, no matter how it is presented, in my humble opinion "In the year 1846-48, Austrian Ida Pfeiffer..." is just not correct. 1846-1848 spans two years, so it should be written: "In the years 1846-48".
Kevin said:
If I were speaking I would say, "In the years eighteen forty-six to eighteen forty-eight"
I agree.
i agree with this Kevin guy
now this guy is great with his answers and all 
teehee
