A.pb=b; B.pb=&b[0]; C.pb=b+2; D.pb=b[5];
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!";