expert 作形容词就是 be expert on/in/at...作名词就是 be an expert on/in/at...或者说 be a world expert on/in/at...等等 expert n.专家, 内行, 能手(in, with, on)熟练者, 有经验者, 老手律鉴定人, 检验人军特等射手an expert in economics 经济学专家an expert with the needle 针线能手an expert on foreign affairs 外交专家习惯用语be expert in ... 在...方面是专家be expert at ... 在...方面是专家 现代英汉词典expert adj.（常与at, in连用）内行的"At a special swimming pool in Los Angeles, children become expert at holding their breath under water even before they can walk." "在洛杉矶的特别游泳池里,孩子甚至在会走路之前就能熟练地在水下屏住呼吸。"Rex soon became an expert at opening the gate. 雷克斯很快就成了开门能手。Kate's an expert in / at / on teaching small children. 凯特是个幼儿教育专家。All the young men are expert drivers. 所有这些年轻人都是驾驶能手。词性变化n.（常与at, in连用）专家an expert in cookery 烹调方面的专家a cookery expert 烹调专家 简明英汉词典expert n.专家, 行家, [军](特等)射手adj.老练的, 内行的, 专门的vt.在...中当行家, 当专家