Which verb form best completes this sentence?

leonardo da vinci el 15 de abril, 1452 y murió el 2 de mayo, 1519.
nace
naciste
nació
nací

Does anyone know what my spanish teacher means by this? i need to use plural forms of the verb ser. and she asked me to use a couple of adjectives to describe the boys collectively and then the girls collectively?

You have been chosen to be the guide of an exchange student from costa rica. before the student arrives in the us, he has asked you to give him some tips about schools in our country. using 10 different commands, create a presentation in which you give him tips for being successful in us schools. your presentation should include 5 affirmative and 5 negative commands in the tú form. examples: study many hours, don’t sleep in class, etc. to create your presentation, you may use powerpoint, or one of the tools listed in the web 2.0 tools area (contact your instructor if you need ).

If the pants costs $233 how would you respond to the question ¿cuánto cuestan los pantalones?