Answer: 1. Voy a hacerla/ la voy a hacer
2. No necesitamos llevarlos/ No los necesitamos llevar
3. Marcos está pidiéndolo/ Marcos lo está pidiendo
4. Debe llamarlos/ Los debe llamar
Explanation:
We use la-las-lo-los according to genre and number of the noun we are referring to. In exercise 1 we refer to the "maleta" which is female and singular, so we use LA. In exercise 2, "Los pasaportes" are masculine and plural so we use LOS. In case 3, "el folleto turístico" is masculine and singular, so we use LO. And finally in exercise 4, "Los padres" are masculine and plural too, so we use LOS again.
