Spanish help? Thanks, only 2 questions ~ Use the correct form of "el" "la" "los" or "las"

Answer: 21-22/ El amigo de Sandra es alumno en la misma escuela.
23-24/ Los alumnos en las clase de espanol son ambiciosos.
Explanation: Hope this Helps! I know these are the correct form of words since I am fluent in Spanish! :D