Answer:
1. Mario les presta dinero.
<em>Mario lends you money.</em>
2. Ellos me escriben mensajes electrónicos.
<em>They write me emails.</em>
3. Juana le vende una cartera.
<em>Juana sells him a bag.</em>
4. La vendedora nos dice dónde comprar trajes.
<em>The seller tells us where to buy suits.</em>
5. Lola te da los calcetines.
<em>Lola gives you the socks.</em>
6. El vendedor les ofrece un descuento.
<em>The seller offers them a discount.</em>
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Explanation:
This is an exercise to practice Indirect Object Pronouns. In all of the sentences above, we can observe how the pronoun comes immediately before the conjugated verb, something that always happens in affirmative statements with one verb.