差速离心法

请让我分清楚SIT和SAT吧!真心分不清SIT和SAT!究竟区别在哪里呢?还有对应起来的话,韩国的又是叫什么呢?丑话说在最前面,有些人别自取其辱,单纯解释英文的真心只让我觉得没文化真心觉得有些 SIT 和SAT 的区别 i know that i have to improve my english是什么从句? I --------know that English is really useful A.get B.got to C.have got to D.have got I ____(tell) that I will have to leave my job.But I don't know what I have done wrong. have的现在分词 have的单三形式是什么?have的现代分词是什么? have的现在分词是什么? have现在分词是什么?having 华宇小学的长是120米,宽是50米,在平面图上用10厘米的线段表示校园的宽,该图的比例尺是【】,平面图上的长应画【】厘米?姐姐的年龄比王芳大六分之一,王芳比姐姐小两岁.王芳有【】岁,姐姐 Have,give的现在分词 某小学校园长是240米,宽是160米,在平面图上长是3分米,宽应是（ ）?A.1.6分米 B.2分米 C.2.4分米 某小学校园的长是160米,宽是100米.在平面图上用20厘米长的线段表示这个校园的宽,该图的比例尺是（）,该图上校园的长应是（）厘米. we had a __with our friends during the Spring Festival A.get together B.get-together friends,during,to,visit,we,like,Festival,the,Spring(连词成句) I'm feeling better,so I want to start(). A.taking lesson B.to take lesson C.taking lessons是不是选B I'm feeling better,so i've startrd taking lessons为什么不用taking lesson I'm feeling better , so i've started _____.a taking lessons b to take lesson c will work d take lesson we ____in the TV station since we moved to shanghaia have worked b worked c will work d a re working请说明原因现在完成时 关于保护校园环境的告示牌学校花园的花草树木经常遭到破坏,请你写几句用以让人接受的话.（不要用禁止、不准等词） we( )"thank you"for our food,familyand friends on thanks giving day.talk say tell speak should we ignore our friends and family for the sake of our own interests?I want to know why rather than what it is 英文字母有哪些 为什么用 现在完成时 have starteda girl who have just started school but whose family can not afford her education 工作几年了英语一直不好,现在着急用口语,想找个英语班提高一下, English是原音字母吗 ____ I have to finish the picture today.回答yes,you do.用must,can,may还是do We often just drop by our friends' Often,we just walk around the town center,seeing as many our friends as we can请问为什么see加ing 帮我用反身代词造句、谢谢 我需要5个不同的反身代词造句、谢谢 run的现在分词running前面要加be吗? they will leave for Canada in 2 weeks' time.（it）is in August 为什么是it 不是that this 速度_____will they have another meeting?-In one week’s time.A.How much B.How soon C.How often D.How long理由理由,急