Spanish HELP!!! Please? quickly?

Yo ___ el sobre en el buzón. (pude, estuve, puse)
Question 2 (Multiple Choice Worth 1 point)
Nosotros ___ a la oficina. (anduvimos, pusimos, supimos)
Question 3 (Multiple Choice Worth 1 point)
Ellos ___ a la biblioteca. (anduvieron, pusieron, supieron)
Question 4 (Multiple Choice Worth 1 point)
Yo escribí la ___ en el sobre. (estampilla, dirección, tarjeta)
Question 5 (Multiple Choice Worth 1 point)
Yo puse la carta en el ___. (sello, sobre, lavabo)
Question 6 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Armando ___ en la piscina todo el día. (estar)
Answer for Blank 1:
Question 7 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Carlos ___ al parque. (andar)
Answer for Blank 1:
Question 8 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Nosotros ___ la dirección en el sobre. (poner)
Answer for Blank 1:
Question 9 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Ustedes no ___ ir al concierto anoche. ¿Por qué? (poder)
Answer for Blank 1:
Question 10 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Yo ___ en la tienda. (estar)
Answer for Blank 1:
Question 11 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Tú ___ la verdad anoche. (saber)
Answer for Blank 1:
Question 12 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Yo ___ mi libro encima de la mesa. (poner)
Answer for Blank 1:
Question 13 (Fill-In-The-Blank Worth 1 point)
Fill in the blank with the correct form of the verb in the preterite tense. Vosotros ___ al teatro. (andar)
Answer for Blank 1:
Question 14 (Multiple Choice Worth 1 point)
Yo pongo UNA ___ en el sobre. (sello, estampilla, correo)
Question 15 (Multiple Choice Worth 1 point)
When used in the preterite tense, the verb "saber" means to ___ (speak, go out, find out).