"Students' Physical Health Standard" stipulates that the test range of throwing solid balls is suitable for students in grades 3-6 of primary schools and junior high schools, senior high schools and universities. Primary school 1 kg, junior high school, senior high school and university test balls weigh 2 kg. 7.8 meters is excellent, not too difficult. Practice! Do more auxiliary exercises to strengthen the strength of upper limbs, lower limbs and waist and abdomen. It's nothing. Difficulties don't scare heroes.