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

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 How has he become an expert at planting fruit tress?(The reporter asked the peasant)改为宾语从句 I’ve become quite……..原句 since I have become quite an expert at ........这句话怎么才能翻得通顺点儿那？ 是be an expert in/at/on ,还是be expert in/at/on? meaning:it was not just what I had become an expert at scraping dirt stuck to their wooden floorit was not just what I had become an expert at scraping dirt stuck to their wooden floor,or that I had learned exactly how to place toys on the girls beds an expert in/on/at有什么区别 an expert in/at/on/with有什么区别?例子：1.an expert in/at teaching small children意思就是说an expert in和an expert at通用对吗?2.an expert in economics3.an expert on foreign affairs4.an expert with the needles it takes years of practice to become an expert.这里为什么practice前面不用the an expert on losing 英语翻译At the bench Howl worked a good deal harder and faster than Michael,putting spells together in an expert but slapdash way.expert在这里怎么翻译? Berkeley是哪?Professor Harley Shaiken is an expert on unions at the University of California at Berkeley. Rex soon became an expert at opening the gate,at后可以用不定式吗?为什么用-ing an expert on和be expert in的区别 be expert in与be expert at 的区别 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 expert at/on/in 有什么区别 be expert at doing 还是in doing