根据题意可得:
x※(4※1)=7,
x※(4×3-1×2)=7,
x※10=7,
3x-10×2=7,
3x-20=7,
3x-20+20=7+20,
3x=27,
3x÷3=27÷3,
x=9;
x※4,
=9※4,
=9×3-4×2,
=27-8,
=19.
故选:C.
根据题意可得:
x※(4※1)=7,
x※(4×3-1×2)=7,
x※10=7,
3x-10×2=7,
3x-20=7,
3x-20+20=7+20,
3x=27,
3x÷3=27÷3,
x=9;
x※4,
=9※4,
=9×3-4×2,
=27-8,
=19.
故选:C.