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....
他在突破警戒线后被一名警察拦截了。He was rugby tackled by a policeman after breaking through police lines.一列拖拉机突破了警戒线，隆隆响着驶上了高速公路。A line of tractors rumbled onto the motorway through a cordon of police.矿工们手持棍棒冲过了警戒线。The miners were armed...
埃迪将自动步枪的保险栓重新拉上。Eddie slipped the safety catch on his automatic back into place.给窗户装上安全锁或窗栓。Fit windows with safety locks or catches.他插上了门(栓).She bolted the door....
Use a template or stencil or simply do it freehand.使用样板或模版，或者干脆徒手画。Serveral of commonly used methods are photoprinting, photoengraving , mechnical engraving, and stencil.通常所采用的几种储存方法是:影印法 、 照相蚀刻 、 机械雕刻和模板.He can stencil ...
Are leukaemia and albinism same kind of disease?白血病与白化病是同一种病 吗 ?What should albinism child notice in nursing daily?白化病孩子在日常护理中应该注意什么?Albinism: ABsence of the pigment melanin in the eyes, skin, hair, scales, or feathers.白...