Answer:
In this exercise, you have to fill-in the blanks using the correct preposition, the options are <em>por </em>and <em>para</em>
Explanation:
The student went for the pencil - El estudiante fué por el lápiz
A house costs at least thirty thousand dollars - Una casa cuesta por lo menos treinta mil dólares
Did you send me the money by mail? - ¿Me enviaste el dinero por correo?
The stone house was built by the Incas - La casa de piedra fue construida por los Incas
Fidel spoke for four hours - Fidel habló por cuatro horas
We go to the beach for the purpose of swimming - Vamos a la playa para nadar
I'll give you $50 for your pants - Te daré $50 por tus pantalones
Andrés took the plane for Barcelona - Andrés tomó el avión para Barcelona
That book is for Manuel - Ese libro es para manuel
The bus goes 100 kilometers per hour - El autobús va a 100 kilómetros por hora
<u>In these cases, </u><u><em>por </em></u><u>and </u><u><em>para </em></u><u>replace:</u>
<em>for </em>in several instances
<em>by </em>in several instances
<em>at </em>(in at least)
<em>for the purpose of</em>
<em>per</em>
