he became an expert 填介词或副词 driving a car

he became an expert 填介词或副词 driving a car Was it in 1998,when he was still at middle school,______ this boy became an expert at computer?A.which B.where C.that D.when 请帮忙翻译：He is an expert in sign language. sales.he is an expert and maketing英文翻译 soon became an expert at opening the gate 句型转换soon （） （） （ ）opening the gate soon became an expert at opening the gate 句 型转换soon （） （） （ ）opening the gate Rex soon became an expert at opening the gate,at后可以用不定式吗?为什么用-ing was it in 2002 when he was agt middle school that the boy became expert at computer?如何翻译 an expert on losing become an expert at 与become expert at 与在新概念第二册的Lesson 59与Lesson 94中出现了,Rex soon became an expert at opening the gate与children become expert at holding their breath under water even before they can walk.其中expert前 he considers himself an expert on the subject 我认为是 he considers himself is an expert on the subject 我是按照中文翻译的就是这样?语法新手. It seems as if he were an expert 为什么谓语动词要用were 而不是was When we talked about the computer,he pretended to be an expert.翻译 He considers himself an expert on the subject,in fact,he is poor on it.怎么译 He did it as if he were an expert.从句表示的动作发生在过去,为什么不用过去完成时 an expert on和be expert in的区别 He is an expert in sales and marketing.for the last three years,mr wang has worked for JHS company. How has he become an expert at planting fruit tress?(The reporter asked the peasant)改为宾语从句