对x求偏导再对y求偏导

What is the easiest way to catch a fish? What is the matter? 问一个口语：what's the catch?语境是V：I brought this for you.B:What's the catch?V:.(忘了) june 真的很喜欢汉语,她可以学到许多关于中国的事情.（really,learn...about）翻译 Tommy's been to the toilet three time this morning.这句话为什么用现在完成时,不用一般过去时?既然句中出现明显的表示时间的状语,应该用一般过去时啊!为什么这里用现在完成时呢?如果是为了强调对 she is communicative about how she feels 请问中文翻译 He has been to Japan three times.(对three times提问) ----- ----- ----- has he been to Japan?还有：We took a minibus to Milkway.(保持句意不变)We ------- to Milkway ------minibus. She _ _ _ everything about China.的翻译 Sally____the park three times.A.have been to B.has been to C.is been to 这道题应该选择哪个? 英语翻译如题,got like怎么翻译, is this Tom的回答 英语vi,vt哪个是不及物动词哪个是及物动词? Is this Tom?的肯定回答和否定回答 Is this Tom speaking?这是电话用语 请问有这种形式吗?还是应将 this 换成 that?哪种对? 这些怎么回答?Is this your son?Is this boy your son?Is Tom your son?怎么区分？ --is this your music p____ ,Tom?--yes,i like to listen to music with it. (Is) Tom (your friend)?(Yes),(it is) .这题是改错,第一个括号是A,第二个是B,第3个是C,第4个是D请你们选选括号里（ABCD）中哪个写错了,在把正确答案写出来. Is your mame Tom?A.Yes,it is B.Yes,I am C.Yes,I'm D.No,I'm no填哪个?为什么? 英语翻译It was,as I have said,a fine autumnal day; the sky was clear and serene,and nature wore that rich and golden livery which we always associate with the idea of abundance.The forests had put on their sober brown and yellow,while some trees the summary of 150字左右,用英语,急 英语翻译The small birds were taking their farewell banquets.In the fullness of their revelry,they fluttered,chirping and frolicking,from bush to bush ,and tree to tree,capricious from the very profusion and variety around them.There was the hones sb.happen to do sth. So you can see ,when (8) happens ,something good may also happen .Steven showed Stuart about books and Stuart showed Steve about basketball .So you can also (9) to show others something that you like to do and they can show you something that they li HAPPEN ON ...这个短语 和sth happen to sb什么区别? happen to do sthI happened _______ when Linda called me yesterday.A.to out B.to be out C.be out D.am out请问为什么 副词能修饰介词吗He says neighborhood police patrols were reduced largely due to funding cutslargely修饰due to?我原来以为副词修饰形容词,动词,没想到介词也一样修饰?还是只有某些特定的副词可以修饰某些特 副词修饰介词一般在什么句子中 英语翻译 one time=once,two time=twice,three time=? 翻译一句话 In this way ,the bat is able to know where things are twice as..as与three time as ...as这两个句型区别是什么啊?都是说倍数的,那分别适用于什么固定语境? DO you know where he lives?对 还是DO you know where does he live?对