No one understands better than Bon Jovi the public's undying love for bombastic ballads sung at vein-popping volume. Bon Jovi swamps These Days with such sap. Only one song makes the boo-boo of aiming for the rock seriousness of U2 the opening ''Hey God,'' which finds Jon Bon Jovi mistaking himself for Job. As for the rest of the album, the group happily forsakes conventional corporate rock for a loud kind of adult pop. Think Whitney Houston with guitars. D

