求z=x^y的二阶偏导数

Ms Smith is the head teacher.对the head teacher提问 where is the head teachermaybe he is in a.Two Room b. the Two Room c.Rooms Two d .Room Two (英译中) 这个小姑娘有点害羞.This little girl __ __ __shyRT 怎么没人说kind of的 你们假期看电影了吗 英文翻译 head teacher的中文 意思是:重视而且恭敬地对待的词语有哪些? 写出下跌动词的s,ing,ed形式be( )( )( )hiccup( )( )( )start( )( )( )become( )( )( )see( )( )( )Nobody saw the man enter the bank改写同义句 ：连词成句too...to,never,young,are,startdong,you,things Have you heard( )（介词）jim yet. 梅花为什么在冬天盛开呢?春、夏、秋季开不开呢? 梅花盛开像什么 梅花盛开着.扩写,至少写两处. shes a head teacher什么意思、 head teacher的汉语意思急! What kind of dog never bites? What kind of dog never bites?2．What rises in the morning and waves all day?3．What’s never used until it’s broken?4．What always speaks the truth but doesn’t say a word?5．Three men were under one umbrella,but none of them got wet.How did what kind of dog never bites?猜谜语 What kind of dog never bites?A.A small doWhat kind of dog never bites?A.A small dog B.An old dog C.A hot dog D.A kind dog 如何用msn和找国外的网友聊天?我的怎么老是中国的网友? 1933年,谁提出来建设“信息高速公路”的计划 headmaster和principal的区别 headmaster是什么意思 Why is six afraid of seven?外教出的题目.帮我想一个超合理的理由好吗?记得用英语回答哦! Why is six afraid of seven? why is nine afraid of seven why is ten afraid of seven?an english riddle 猜谜：Why is nine afraid seven? Do you think this present is ___________ for a little girl?A.sufficient B.qualified C.suitable Do you think this present is ___________ for a little girl?A.sufficient B.qualified C.suitable D.useful 请问哪个对呀? Do you think this present is suitable for a little boy.suitable 可用suit换吗 可用right换吗 或是careful What do you think of this girl?最近有个女的在纠缠我.她是我的好朋友.因为我知道我这人长的很一般,还有点胖.唯一的优点就是前途比较光明,呵呵.她主动对我示爱,可之前在她身上发生的一些事情 where has this letter come from能把has换成is吗?两者有什么区别? 我曾经收到她的三封信.是这样翻译吗?I have ever heard 3 letters from her. 现在经常看到有人在中文后加上'ing"请问是什么意思啊