哪种脊椎动物最早出现在地球上

yw somebody weekend和weekends有什么区别?on weekends和on weekeed分别是什么意思?区别又是什么?还有另一个语法,he's smarter than me.为什么还有的是这样说 I'm quieter than he is.me 和 he is 又不是同一个形式?为什么可以 英语：at weekends为什么不用on weekends?详细! 帮忙写一篇英语作文:on weekends1.你通常会在周末做些什么呢?根据下面的事情任选一个写一篇小作文；2.条理清晰,意思明确、连贯,句子通顺,标点正确,书写工整、规范；3.不少于60个单词；事件 1.A book is like a garden carried in the pocket.2.Honesty is the best policy.3.A lazy younth,a louzy age.4.Homer sometimes nods5.He who knows others is learned,and he who knows himself is wise. 连词成句,帮个忙用playing are playground the in we like games造个句,帮个忙.（有具体动词like,无法造一般疑问句）（级别在四年级以上）我在《怎样学好牛津英语》三年级的P50页的第（3）. at,take,we'll,quarter,eleven,bus,a,past.；连词成句 连词成句 帮个忙啦芳心 怡悦 云翳 岩巉 枭鸟 心魂惊骇 休憩 庇荫 骄奢 选3---5个词语,连成一句话,完整,流畅 有on the weekends吗它什么意思? on weekends 改错 She gave him it last night. drawing为什么不双写w 加 ing? We have finished this task and are waiting for_one.答案是anthor 但我想next也行啊 the 1st day of July和this 1st of July对? weekends的意思 weekends是什么意思 weekends是星期的意思吗 Would you mind ___(close)the windows?The men spent 1 hours___(finish) drawing the picture.用所给动词的适当形式填空最好说个理由哈~ It took us 2 days [ ] [finish] drawing the picture He (花费）five hours in finish drawing the picture怎么填 i ll chat you after somtime take care翻译where you reach？翻译 求英译“门卫处” spring summer fall 这首歌的发音 spring和please的p读音是否一样?快 a b如何求 I s the heavy rain harmful _the crops?A.for B.atI s the heavy rain harmful _the crops?A.for B.at C.with D.to答案是D为什么不选A呢?be harmful to与be harmful for有什么区别? 1.You must finish ___(draw) the picture.2.I am sorry I really don`t know what ______(do).3.Thank you very much for ____(invite) me to your party.4.It takes me half an hour _____(get).用所给动词的适当形式填空 Can you finish( ) (draw) the picture in two days?要不要加ing大神们帮帮忙 you discover facts that show that it is definitely true.这句语法对么,为什么两个that, 7.6km/s等于多少米每秒啊? s谁知道8个8相加等于一千 集合A={1,2,3,4,5,6}B={4,5,6,7,8}则满足S包含于A且S交B不等于空集的集合S个数为