¿Qué tienen en común estas tres plantas la rosa ,cactus y cardo

Calcula la concentracion de hidronio en la lluvia ácida si el ph es 4.35

Question 16 (fill-in-the-blank worth 1 points) fill the blank with the preterite tense of the verb in parentheses. ella guitarra anoche. (tocar) answer for blank 1: question 17 (fill-in-the-blank worth 1 points) fill the blank with the preterite tense of the verb in parentheses. yo mi abuela la semana pasada. (visitar) answer for blank 1: question 18 (fill-in-the-blank worth 1 points) fill the blank with the preterite tense of the verb in parentheses. los señores la banda ayer. (escuchar) answer for blank 1: question 19 (fill-in-the-blank worth 1 points) fill the blank with the preterite tense of the verb in parentheses. yo el supermercado la semana pasada. (trabajar) answer for blank 1: question 20 (fill-in-the-blank worth 1 points) fill the blank with the preterite tense of the verb in parentheses. tú una falda roja. (llevar) answer for blank 1:

Fill the blank with a la, a los, a las, or al. los alumnos