Let $ a◆b=a+(2\times b)$, then $1◆(2◆3) =$~\uline{~~~~~~~~~~}~. 
Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Operating Directly
$1◆(2◆3)=1◆[2+(2\times3)]=1◆8=1+16=17$.  So the answer is $\rm C$. 