A.x=pa[3]; B.x=*(a+3); C.x=a[3]; D.x=*pa+3;
A.double p=&k; B.int *p=&k; C.double &p=*k; D.char *p="Thank you!";
A.int p=&m; B.int *p=&m; C.int&p=*m; D.int *p=m;