What does pink and yellow make?

Which of these expressions is the most casual way to greet a friend

Choose the correct use of the spanish preposition para in the following sentence. para aprender un idioma bien, hay que practicar fuera del salón de clases. "in order to," followed by an infinitive "to," referring to a destination "by," referring to a deadline intended for a goal or destination

No debemos el medio ambiente. a. contaminar b. preservar c. desechar d. cumplir