求z=x^y的二阶偏导数

Tow hours ( )the limit of this test A are B has been C will be D is 选什么啊,原因? need,a,for,sister,I,buy,book,my,to连词成句,秒回秒采 () of the price for an adult,and a child under 1.10()go into the zoo free.第一空A、all B、one C half第二空A、do B、is C、can He said,"I was late for school." 间接引语是He said that he was late for school为什么不用过去完成时 Group size:At least 20 people Price:6 for children 8for adults-IFREE adult every 20 paying childrenI发3 teachers and 40 students visit the park,they shouid pay _________.A.240 B.264 C.248 D.320 () of the price for an aduit,and a child under 1.10()go into the zoo free i do not think i will refuse eating out in the open air翻译成中文是什么意思 ()Having a party in the open air will be __A:funB:a funC:funnyD:the fun I don't think he will do it和I think he won't do it那个对,为什么? no music no life no speed no their 什么意思 中国是怎么被翻译成dragon的啊 exam可不可数?后面可以加s吗?如果是不可数名词,后面用is还是are? “exam”是可数名词吗回答即可 exam是可数名词还是不可数? exam的全称是什么 u hope u can stay my place after we go outhave fun at my I konw the teacher______to Amy when she ______ of a bright girl.A.was referring,spokeB.refers,has brokenC.referred,was speakingD.was referring,was speaking又说选A又说选c我就想知道为什么呢? paper作为试卷可数吗? I 'm tired of talking什么意思 From space the earth looks like a water planet.为什么不倒装 为什么seem from the moon,the earth looks like a blue water globe要用seem而不是seeming i have a voice too Passive voice:You have to see it to believe it.1.You have to see it to believe it.2.We know that you were in town on the night of the crime.3.Who wrote it? I don't think he knows my pen pal,___?A.doesn't he B.does he C.don't you D.do youthe poor young man has__money but__friendA.little;fewB.little;a fewC.few;a littleD.a few;little【理由】 内含子和外显子数量是否一样 jack _____(锻炼)in the park every morning to keep fit my sister drives to work every morning Morning every morning sister!是什么意思 王老师,有2014最新人教版新目标英语八年级下的单词+课文的MP3没有 a true friend is the greatest of all biessings.