The missing words in the presented sentences are: 1. cerrada, 2. preocupado, 3. cansado, 4. aburrido, 5. enojada, 6. sucio.
<h3>How to identify missing words?</h3>
To identify the missing words in each sentence, we must review its basic structure, making sure that it has a subject, verb, and complement.
Additionally, we must identify to which category the missing words correspond, in this case they are adjectives. According to the above, the complete sentences would look like this:
1. Si la puerta no está abierta, está cerrada.
2. Marco está preocupado porque tiene un examen hoy.
3. Juan necesita dormir porque está cansado.
4. Felipe está aburrido porque no encuentra nada interesante que hacer.
5. Ana está enojada porque no encuentra el libro que busca.
6. Debes limpiar el piso porque está sucio.
Learn more abour adjectives in: brainly.com/question/11385993