已知{An}是公差为d的等差数列,它的前n项和为Sn,S4=2S24,Bn=1An/An求d

I Have a lot of friends and money! I think there are some babys in the house.(哪写错了?) Our teacher often tell us_______to others A.friendly B.be friendly C.to be friendlyA.friendly B.be friendly C.to be friendly D.are friendly Police have found what appear to be human remains.请翻译一下. 英语翻译请教found后面的句子怎么翻译 the police dag are specially trained to seatch and find berglary suspects翻译 Who is the person that is standing at the school gate?这句话的意思? This man who is standing by the gate is difficult to ___.A.take apart.B.do with.C.deal withD.sort out Don't ___________ at the old man like that.最后一个字母是t,共5格: _ _ _ _t The man that I like is the one who is both competent and diligent怎么解释 杜甫诗《房兵曹胡马》胡马大宛名,锋棱瘦骨成.竹批双耳峻,风入四蹄轻.所向无空阔,真堪托死生.骁腾有如此,万里可横行.“骁腾有如此,万里可横行”的“横”字可替换吗?没有什么好的建议吗 be friendly to 等于什么 横行该怎么读 be friendly to还是with 还是for? be good with 和be friendly to 的区别 be friendly to sth与be friendly with sth有什么不同? 三毛流浪记读书笔记跪求2000字三毛流浪记读书笔记！ 英语翻译一句翻译一句的 把诗句每一个字都组成一个词语把这个诗句每一个字组成成语,比如：（ ）白（ ）（ ）,（ ）日（ ）（）,诗句是：白白日依山尽,黄河入海流.急死了 rosetta stone的激活码是什么用rosetta stong学重点的时候需要激活码 what she did surprised us请问这里的surprised还是形容词还是动词? 谢谢.还有this news surprised me也是。 请问rosetta stone的ISO具体怎么用你能跟我具体说一下吗? someone is living in my heart someone is living in my 我想要最正确的翻译虽然没分给你们祝你们全部健康 someone is living in my heart韩剧对不起我爱你的译文 someone is living in my heart译音歌词 骁腾有如此是什么诗 求含有骁字的古代诗句..含有骁字即可.唐诗宋词元曲均不限.格式主题内容等等也不限.急! It the thought that 这好像是个谚语 开瓶器的支点和阻力点在哪里? 三凹征的概念是指什么RT 请问开瓶器的支点,用力点和阻力点分别在哪里?手向下压的位置( )靠在铁桶边缘的位置( )插在盖子底下的位置( ) 医学上“三凹征”是什么?