网络教育本科二学历

关于机械波：为什么只有相差半个周期速度才会相同 机械波振动时间超前已知点A振动方程,波向右传播,取向左为x轴正方向,为什么波线上任意点振动时间比A超前x除以u（不理解时间超前是什么意思）.另外一道题x轴向右又变成任意点时间落后了 入射光线与镜面夹角为30°入射光线不动旋转镜面入射光线与镜面的夹角变为35°,则反射光线的传播方向将改变为什么? Because it's interesting什么意思?v it's difficut but interesting 如何设计实验证明二氧化锰反应前后质量不变?是和双氧水反映的实验中谢谢一楼的回答...看不大懂哈...本来想用天平的..但是偶觉得质量太少无法测得.. It's quite dangerous,but very exciting 翻译成中文 do you want to () a policeman too ? oh ,yeah sometimes it`s kind ()dangerous ,but it`s also a veryexciting () 填空do you want to be a bankclerl () ? no,not really ,i want to be() repofter. oh ,yeah()?it`s very busy , () it`sfunny,too.i can He always_____ weekends playing with his kids.A.spends B.visits C.pays D.takes 求助啊兄弟手机现在开机无限出现CWM-based Recovery一开机出现的画面先是M 然后自动亮蓝灯 自动进入以下画CWM-based Recovery v4.0.1.5-defy.大哥 I began to learn Janpanese 2005请问中间到底填什么? 翻译identification of key employees on leave,current salary and all pending increases simulink仿真的时候怎么把多个scope的图形重叠起来在一个scope里面观察? simulink仿真时,怎么把scope窗口的图形精确读出数据?经过仿真画好一个图形,但是要读出第一个和第二个波峰值,看是scope上面的刻度不太精确,怎么才能读出精确的值啊? simulink中用scope观察PN序列如下图,怎么解决? They began to learn farming two years ago(同义句转换） 关于酸的化学式我有些问题不大明白.含氧酸化学式的角数是怎么确定的? Daniel bagan to learn Japanese two years ago.用for two years 改写） 九年上,我想知道怎么区别几个分子,或者是几个原子什么的,就是说2CO2是两个二氧化碳分子,那为什么不是两个二氧化碳原子,还有2Fe,为什么是两个铁原子,而不是两个铁分子,还有；磷价不是3,5 制度在经济发展中起到的作用? Time is a file that wears and makes no noise翻译成句子是什么意思?各位高手帮帮忙,谢谢!注意是翻译成句子,在百度翻译上翻译不成句子~ 求翻译：secure information about work permits and approval process and taxes 英语翻译.Extension application of the guarantee shall be raised to issuing bank before the above expiry date with sufficient supporting document,and extend or not depends on issuing bank’s approval. cwm-based recovery v6.0.4.5怎么卡刷 看不懂英文 The editor acted as he did because he was dissatisfied with the factual content of the article.请翻成中文 The newspaper ____editor was fired.Because he was not good in quality.A.whose B.thst C.which D.of which 选择A和选择D呢 求酶反应的反应图. I'm Gina.同义句转换如题 I'm Gina.同义句转换 __ __ Gina 有谁知道酒店台布该怎么铺设? 铺天盖地的意思是什么? 铺天盖地什么意思 铺天盖地的意思词语意思!1