求證(x-x1)(x-x2)+(y-y1)(y-y2)=0

Il restera à Paris____un mois.答案是pour,请问可以用pendant和en 如果不可以求解释原因,还有为什么只能用pour呢? 系动词中变化系动词 持续系动词 还有感官系动词 此类系动词后表语都是形容词或分词 是为什么? 冷血动物用英文怎么说?急 8月30号和31号的新闻摘要 能帮我改成英文吗老师要用英文写这两天的新闻 可有些语句怎么也写不出来啊 有谁能帮帮忙 急用 Don’t you think it is a good idea for the future什么意思? The idea of punishing a tiger that kills somebody is absurd,for exactly the same reason,so is the idea that tigers have rights.However,this is only one account,and by no means an uncontested one.exactly如何翻译for exactly the same reason又如何 动词分词能做定语的都能做表语吗 动名词和动词ed作定语有什么不同?A small man looked out of an opened window ,为什么不能用opening 分词作定语跟表语的用法They are cleaning the fallen leaves in the yard.他们正在打扫院子里的落叶.（做定语）They are gone for vacation.他们度假去了.（做表语）像这些句子中为什么动词fallen gone 用过去 one of its amplifiers channels will be broken when the machine is working. if the machine is workingplease ______ it.A.not touchB.not to touchC.don't touch为什么.错了错了答案是B 为什么啊啊啊啊>/// fortunate son中文歌词回味黄金时代的歌曲 如何翻译 The Edmund Fitzgerald 英语翻译spray bar 、heel unpack the picnic basket翻译 Today is ____Easter Sunday.I'll buy ____Easter basket.A.the,a B.a,the C.不填,an D.the,不填 This an Easter He's good at English.(同义句）谢谢大家 He is good at English.和at English是什么意思 翻译（简洁,优美）：life help those who are ready to help themselves You______ _______ _______ he_____good at English.中间应该填什么?你和他英语都学的很好这是意思. Brothers Forever Shall we ____(字母o开头）a taxi now? 怎么移民加拿大?我现在是个学生,是个T以后有想去国外的想法,因为在中国真的太多压力了,再有就是我不仅要自己过去,还要带着我的她,是要投资过去还是留学,还是怎样?麻烦高手们给点意见 Why does you love who does not love you?有没有语法错误 son的意思 son 是什么意思? son啥意思 THE SHORTEST HISTORY OF EUROPE怎么样 son是什么意思 .--- Do you know the young man was charged ______shoplifting?---But I don't think he is guilty __.--- Do you know the young man was charged ______shoplifting?---But I don't think he is guilty ______that crime.A.for; of B.with,of C.of; with D.with,for son是什么意思?