The summations of forces in this and that directions must be zero.在这个和那个方向上的合力必定为零.Summations are almost invariably indicated ellipses instead of the more prevalent sigma notation.在表示“连加”的式子中,几乎一成不变地使用省略号来代替更为流行的“∑”符号....
So Miss Ellen , she tuck an'nuss dem too.这样,爱伦小姐就得同时护理她们了." Gimme dem lines,'said Sam, snatching the reins from her." 把缰绳给我, "萨姆说着, 就把缰绳从她手里抢了过去.Huccome you din'ast dem ter stay fer supper, Miss Scarlett?你...