A.int p=&m; B.int *p=&m; C.int&p=*m; D.int *p=m;
A.x=pa[3]; B.x=*(a+3); C.x=a[3]; D.x=*pa+3;
A.for B.while C.do-while D.switch
A.1 B.2 C.3 D.4