<em>Generalmente duermo _________ cinco horas</em>.
Translation:
Generally, I sleep [blank] five hours.
<u>The options</u>
- <em>con</em> - with
- <em>de</em> - of
- <em>para</em> - for
- <em>por </em>- for
As <em>con </em>and <em>de </em>don't work in this context, we have to choose between <em>para </em>and <em>por</em>. Both mean "for" but they are used in different situations. <em>Para </em>is used to speak about objectives (among other things), and <em>por </em>is used to talk about duration (also among other things).
Five hours is the amount of time you sleep, i.e. the duration of your sleep, therefore the answer is <em>por</em>.
Answer:
<em>por</em>
<em>Generalmente duermo </em><em>por</em><em> cinco horas</em>.
