Spanish language Q&A Forum

I've read the Q&A and related articles and am still confused. The sentence is: My sisters are often late, I always wait for them for two hours. When I apply the information in the lesson's Q&A, I ask myself: "For whom do I wait? For my sisters." Therefore sisters should be an indirect object. However, the quiz gives the direct object pronoun, las, as correct. Which is it and why? (Also, it would be helpful if you edited the questions so the correct answer to this appears consistently.) 

ps: it looks like Marcos and Lisa, below, are asking the same question in slightly different ways. Perhaps you can address all 3 questions as a group. Thanks!

The translation of the sentence is missing. Why is there hubieras after si?

Is the conjunction que missing in two of these options including a correct one?

How does "could" translate from "Dónde estará esa chica?" Isn't that future tense?  Would "¿Dónde podría estar esa chica?" be more correct?

Hola a todos,

No hay muchas carreteras ________ conducir despacio. There are not many roads where one can drive slowly.HINT: ¿Dónde or donde?
Although the required answer here is ‘donde’, I instinctively want to write ‘donde se puede’.  So it’s ok to leave out the ‘se puede’= ‘one can’ and just use the infinitive, in this instance ‘conducir’?  I appreciate that this quiz is only to determine whether to use ‘donde’ or ‘dónde’ but it just read oddly to me. 
Gracias :)

Hola,

The example given is "No vimos nada desde nuestro asiento" and is translated as "We couldn't see anything from our seats." Should the phrase read "desde nuestros / nuestras asientos?