Can someone answer these three questions for me? Thank you.

20. For the reaction: 2SO3(g)2SO2(g)+O2(g) Hr=197.8kJ at 298K. This reaction will A) be driven by the enthalpy C) not be spontaneous at any temperature B) not be spontaneous at high temperatures E) be spontaneous at all temperatures D) be spontaneous at high temperatures 21. Consider the following reaction: CaCO3(s)CaO(s)+CO2(g) If this reaction is endothermic, which one of the following statements is true at 298K and 1atm ? A) Gr is positive at all temperatures B) Gr is negative at high temperatures C) Gr is negative at low temperatures D) Sr is negative E) Hr is negative 22. Which one of the following statements is true? A) Spontaneous reactions always have Hr0 E) Spontaneous reactions always have Gr>0