读课文《纸船》,填空:母亲,倘若你梦中____/不要____/这是____/____。
During holidays,Kitty usually goes to see the exhibits in many museums,such as the history museum,the art museum,the museum of science and technology and the museum of natural history.There are thousands of wonderful things in museum.There are paintings,sculptures(雕塑),costumes(服饰),swords(剑),ancient animal bones and plants,stuffed animals(动物标本)and many others.It is always a good review of history to visit those museums.It is also a great way to learn more things by myself.
①将乙醇和乙酸、稀硫酸共热制乙酸乙酯
②无水乙醇和浓硫酸共热到140℃制乙烯
③验证RX是氯代烷,把RX与烧碱水溶液混合加热后,将溶液冷却后再加入硝酸银溶液出现褐色沉淀
④做还原性实验时,当加入新制的氢氧化铜悬浊液后,未出现红色沉淀⑤检验淀粉已经水解,将淀粉与少量稀硫酸加热一段时间后,加入银氨溶被水浴加热后未析出银镜
⑤检验淀粉已经水解,将淀粉与少量稀硫酸加热一段时间后,加入银氨溶液水浴加热后未析出银镜
文言文阅读 ,回答相关问题《论语》十二章子曰:“学而时习之,不亦说乎?有朋自远方来,不亦乐乎?人不知而不愠,不亦君子乎?”曾子曰:“吾日三省吾身:为人谋而不忠乎?与朋友交而不信乎?传不习乎?”子曰:“温故而知新,可以为师矣。”子曰:“学而不思则罔,思而不学则殆。”子在川上曰:“逝者如斯夫,不舍昼夜。”
如图所示是测定额定电压为2.5V的灯泡的电功率的电路.完成下列问题: