Indique si los sistemas son abiertos, cerrados o aislados:
1. Gas que se expande en un cilindro provisto de un embolo.
2. Caldera de una máquina térmica
3. Cohete .
4. Vaso con agua .
5. Termo lleno de agua caliente
6. Estadio .
7. Una planta desalinizadora de agua de mar .
8. Helio contenido en un globo que se calienta bajo la acción de la radiación solar. .
9. Lata de gaseosa dentro de una cava de icopor o de anime .

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous