S1: $\bar{L_{1}}$ - ${L_{2}}$ : True
it can be written as $\bar{L_{1}}$ $_{\bigcap }$ $\bar{L_{2}}$ , L2 is given as CFL and CFL is not closed under complementation and it will fall in 1 higher class of language CSL.
S2: $\bar{L_{1}}$ - $\bar{L_{2}}$ : False
it can be written as $\bar{L_{1}}$ $_{\bigcap }$ ${L_{2}}$ , which is again not closed under intersection/union.
If L1 and L2 are CFLs, then L1 ∩ L2 may not be a CFL.
Both CFL and DCFL are closed under intersection with regular sets.