Morning exercise drills in Beijing become a bit strained for Chinese soldier at right as his hat begins to slip. The hats are turned upside down to sharpen the soldiers' senses and refine their posture, a crucial element in their many official duties. Meanwhile, the general political department of the People's Liberation Army has ordered the military to study a warning by Communist Party chief Jiang Zemin that political mistakes by party cadres could spell the downfall of party rule.