望远镜的物镜必须精确置于中心上.The object glass of a telescope must be accurately centred.此物镜仅产生很小的散射光.This objective produces only very little scattered light.由单透镜组成的物镜可作目视和照相观测用.Objectives which consist only of one lens can be used f...
Philip paced the floor, a typically nervous expectant father.菲利普在地板上踱来踱去，一副典型的神经紧张的准爸爸形象。He paced the corridor, hands clasped behind his back.他双手紧扣，背在身后，在走廊里踱来踱去。His fast-paced novels are full of bizarre situations and m...
This driving mode allows you to move off in third gear to reduce wheel-spin in icy conditions.在这个驾驶模式下你可以挂3挡起步，以减少轮子在结冰路面上打滑的现象。The lorries were lined up, ready to move off.卡车都排好队, 准备出发.A few minutes later, the whistle s...
Through the separation, lignosulfonate with narrow molecular weight distribution was obtained and then chemically modified.木质素磺酸盐是一种常见的普通减水剂, 其分子量分布较宽,从而影响减水剂性能.The graft mechanism of lignosulfonate and acrylic acid was ...