4、where is it？

A.SELECT &1, "&2" FROM &3 WHERE last_name = ‘&4‘;

B.SELECT &1, ‘&2‘ FROM &3 WHERE ‘&last_name = ‘&4‘‘;

C.SELECT &1, &2 FROM &3 WHERE last_name = ‘&4‘;

D.SELECT &1, ‘&2‘ FROM EMP WHERE last_name = ‘&4‘;

A.ALTER TABLE student where id＜4;

B.UPDATE student set grade=100 where id＜4;

C.UPDATE student set grade=100 where id＜=4;

D.UPDATE Table student set grade=100 where id＜4;

A.which()

B.what()

C.when()

D.where()

A.ALTER TABLE student where id＜4;

B.UPDATE student set grade=100 where id＜4;

C.UPDATE student set grade=100 where id＜=4;

D.UPDATE Table student set grade=100 where id＜4;

A.ALTER TABLE student where id＜4;

B.UPDATE student set grade=100 where id＜4;

C.UPDATE student set grade=100 where id＜=4;

D.UPDATE Table student set grade=100 where id＜4;