绳子拉船为什么分解船的速度

i have been to shanghai为什么加been?完成时态 have+done是没错可这里为什么叫用be动词? 磁现象是怎么被发现的? a temporary visitor什么意思 familiar什么意思 偏心轴着么算的 visitor-days什么意思 l have been to Shanghai和l have been Shanghai哪一句句子对you can go to d____ museums and theatres to see plays and films i have not been to shanghai.这句英语为什么要用 beenhave been是固定用法吗 能发出建造生物体自身生命大厦蓝图的一系列结构是 A细胞壁 B细胞膜 C细胞质 D细胞核 细胞中为生命活动提供能量的结构是 a.细胞壁 b.细胞核 c.细胞膜 d.线粒体 英语翻译He thought the sign had made him look silly.But the sign hadn’t,— getting angry had made him look silly.There is a difference between people laughing “at” you and people laughing “with” you.When someone plays a trick on you an looking cool 翻译? 振动筛的规格大小除了和产量有关还有什么不同? 振动筛是如何处理污水的 Recently a visitor damaged 什么们意思打错了！！是Recently a visitor damaged it haven't been to.和haven't gone to 的区别 1.I want to find some information about hainan.would you teach me__todo that on the Internet?A.what B.when C.where D.how2.The teacher asks me not__tricks on others.A.to play B.play C.plays D.playing3.Do you often get up __six __the moring?A.in,on B.a “For those who haven’t been to Tibet ,Tibet is a dream :for those who have a_____ been there ,Tibet is a remembrance(记忆),”said Li Wan,a graduate f________ Zhongshan University.“To local Tibetans,Tibet is a way of life .But to me ,living t 荷花出淤泥而不染,与此相关的结构是( ) A.细胞壁 B细胞膜 C细胞质 D细胞核细胞壁有保护和支持的作用细胞膜控制物质的进出,进行物质交换的功能,也有保护作用那么这个题目到底选A还是选B my father hasn't been to Tibet.I haven't been to the Tibet,either.填空,题意不变变为my father hasn't been to Tibet,and ____ ____ i. 串联电路中,电阻越大电功率越大还是越小?为什么有的人说电阻大电功率越大有的人说越小?根据p=I^2R,串联电路中,电阻越大电流不是越小吗?然后电功率就越小对吧?为什么每个人都说因为串联 For those of you who haven't been outside lately,it's a jungle out there.怎么翻译 从细胞结构上看,“种豆得豆,种瓜得瓜”这种现象,主要决定于什么? 1、从细胞结构看,“种瓜得瓜,种豆得豆”主要决定于：（ ） A、细胞壁 B、细胞膜 C、细 为什么说串联电路中电阻越大功率就越大 谁知道这是啥玩意, 谁能告诉我这是啥玩意?这是什么东西?长得像人一样.. 这是啥玩意 出现这个玩意是啥意思?应该怎么弄 We need friends to share happiness and sorrow句尾为什么不加with? 我是wekx123.不知能否用电阻来代替大功率电器.或在此电路上串联电阻或串并联几个电容?计划用交流电制取氢气(有图片,而且已争得父母同意）是否可行?提问者,最好详细一点,若答得好,多加你 在protues中为什么我接一个led串接一个电阻1k的怎么不亮呢?