必要而充分的条件是合外力矩能量小于最大限度的恢复能量，且合外力不等于零；

What is necessary is resultant moment energy is smaller than maximal rehabilitating energy and is not zero.

youdao

必要而充分的条件是合外力矩能量小于最大限度的恢复能量，且合外力不等于零；

What is necessary is resultant moment energy is smaller than maximal rehabilitating energy and is not zero.

youdao