不等式等号成立条件

关于物体的投影与影子下列说法正确的是A物体的投影就是物体的影子B物体的影子就是物体的投影C物体的正投影就是该物体的主视图D物体上方有一灯光源,则该物体的影子就是该物体的俯视 “只有投射到一个面子上的影子才叫投影”怎么理解“并非所有的影子都是投影,只有投射到一个面上的影子才叫投影”,那几个电筒照射一块木桩所产生的影子是投影吗?如果不是为什么? 曾子杀猪里曾子和他妻子谁对孩子的教育是对的?曾子的教育主张是什么 “机不可失,时不再来.”的意思 1/2×（ ）=（ ）×18/7=1×（ ）=3×（ ）=1 英语课堂上的口号 可以是汉语,也可以是英语 要积极向上的 山一程,水一程 风一更,雪一更 从这些词句中你个想到了那个成语?傻子不来 积极向上的用英语怎么说怎么不来个级别高的回答呀 The students would like_(play)football after class用所给词的正确形式填空 1.“机不可失,时不再来”.这句话强调的是时间的（ ）. After supper,the students play the piano.(对After supper提问）. 用"得饶人处且饶人""机不可失,时不再来"写几句连贯的话. 关于校园的标语,30字之内,积极向上 parents your at are home ) 连词parents your at are home )连词成句 My parents are (at home)括号进行提问() ()your parents? Are your parents at home?还有 This is my uncle Henry Brown.(对uncle Henry Brown部分提问) Those boys and girls are my classmates.(作否定回答) This flower is very beautiful.(将名词单数改为复数) 似乎有点难--------英语填空{顺便说明理由好吗?}1.My family ____{move} to France the day after tomorrow2.He was badiy ill and we ________{take} him to hospital Last month we asked our students about their free time activities.翻译成中文 Last week I asked students about f______. compared with last year,our pay___about 500 yuan every month,有四个选项,选什么,A.has increased by B.has increased C.increased by D.increased to能说说选什么,说下这四个选项的区别与用法吗,参考答案是B, Compared with last year,our pay _____ about $500 every month.Compared with last year,our pay _____ about ￥500 every month.A.has increased by\x05\x05\x05\x05\x05B.has increased C.increased by\x05\x05\x05\x05\x05\x05D.increased to课本是这样的th goodand,you,your,parents,at,are连词成句good，and Go up the street until you go to the end.（同义句）Go up the street（）（）（）. 同义句转换 Go up the street to the end. Walk on _______you _______ _______ the street.Go up the street to the end.Walk on _______you _______ _______ the street. ----i'm sorry ,i'm late -----it ______ matter this time 一直往前走,直到第一个单行街.Walk ( ) until you ( ) to the first one-way street.根据中文填空 Go ____ the street until you get to the bookstore.There you can find the school.A.long B.along C.straight D.ahead请说明原因什么的,也翻译整句 冠和萍字有组成的成语吗 能不能把 伟字跟萍字 组成个成语 雄和萍字组成有意义的成语 【萍】字成语或者有带【萍】字好的形容词? 描写瀑布气势大的成语