性格坚强的的英文：
forceful
Their breezy, outgoing personalities were strong and attractive.
她们活泼开朗的性格是坚强可爱的。
adj. 强有力的；有说服力的；强烈的；坚强的
by (main) force
用蛮力, 全靠气力; 以最大的力气
The force is spectacular!
这个瀑布很壮观！
resultant force
合力
The threat will force greater dispersion of their forces.
恫吓将迫使他们把兵力铺得更广。
The tension force, shear forces (including pushing force, cutting force and friction force), impulse force, hydrodynamic drag on the suction pipes, and the force resulted from the pressure difference, etc, are the main forces for detail discussion in this paper.
详细讨论了主要作用力：在波浪补偿器作用下的缆绳拉力、耙头与海床间的土壤剪切力、作用在耙吸管上的水流阻力及由于压力差在耙头处产生的推动力等。