y=ln(1+x^2)的n阶导数

sleep的过去式和过去分词 英国话叫英语 美国话为什么不叫美语 英语为什么是世界语言?美国的语言跟英语相同吗 sleep的现在分词 sleep的动名词好的有赏! 跪求一本外语书的听力,外贸英语口语大全-美语会话脱口秀系列,李雪主编的,光盘陪我弄丢了,现在在学,没有听力难受死了 英语翻译 his brother often wears a pair of blue jeans.（写出同义句） 变成：his brother （ ） often （ ） a pair of blue jeans两个空里分别填什么? He often _____a pair of blue jeans.(选择)A.puts on B.wearsC.in D.with I'll always be by your side support you ,walks out ,I'll always believe you ,my heart will go on 英语倒装Seldom does he go out为什么不用seldom does he goes out到底哪个对 理由 He always does this原文：What had happened to the writer's bag?After I had had lunch at a village pub,I looked for my bag.I had left it on a chair beside the door and now it wasn't there!As I was looking for it,the landlord came in.'Did you have a They enjoy swimming in summer.(改为同义句） They___ ___ swimming in summer. He writes a letter to me every three months.(改为同义句）He writes to me _____ _____ two months We should watch TV once a week .(改为被动句） TV should _____ ____once a week .谁若知道就告诉我,谢 We watch TV once a week(对 once a week提问) Mike _____ (do) his homework every day and he ____ (watch) TV once a week. We should take a s_____ once a week We should take a s_____ once a week 根据首字母提示写出单词 do的过去式是什么啊? do的一般过去式是什么? did的过去式请问did有过去式吗?为什么英语练习册上有这一题：写出下列单词的过去式：.did（ ）该怎么填呢? 英语翻译 I can water the flower.改为一般疑问句 Tome and Jacky can water the flowers.(改成一般疑问句,并作肯定回答)最好带有方法,简单易懂的, 请帮我用never.usually.everyday.often.sometimes.once a week.各造一个一般现在时的句子! I can water the fiowers.变一般疑问句并作否定回答. it is pleasure to meet friends coming from afar这里afar的词性是名词还是副词,from+副词能行吗? get down;get on with;get on以上这些词的用法区别 请问,除了英语,汉语,还有什么语种好学?就现在的形式,希望是亲身经历过的说一说详细点 外国人坐着围在一起讲故事,分享一些自己的观点,在全名超人汉考克里有过,无敌破坏王里也有过,怎样理解这项……活动? 如果学小语种的话哪国语好学而且吃香?