$2-$ A process occurs in an isolated systems of the system if the process is adiabatic.

a$)$ Isothermal.

b$)$ isobaric.

c$)$isochoric$.$

d$)$adiabatic$.$

$3-$ According to the second law of thermodynamics,

a$)$ Heat can flow spontaneously from cold system to hot system.

b$)$ Heat can flow from cold system to hot system by applying work.

c$)$ The heat engine can convert the heat totally to work.

d$)$ The heat added to the system equal to work and change in internal energv of the svstem