出口食用动物饲用饲料登记备案证有效期( )年。
A.5
B.4
C.10
D.3
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唐代诗人张继写的著名七绝诗《枫桥夜泊》中前两句是:“月落乌啼霜满天,江枫渔火对愁眠”.这是作者乘船在苏州枫桥停船过夜的感受.在“月落乌啼霜满天”这句诗里,包含了哪些物理知识?请写出由这句诗可以直接联想到的相关物理知识,并作简单的解释.(请至少写出4个)
解答示例:光的反射:月球反射太阳光,使人看见月亮.
(1)______.
(2)______.
(3)______.
(4)______.
(5)______.
(6)______.
A long time ago, there was an emperor(皇帝). One day he told his horseman that if he could ride on his horse and 26 as much land area as he liked, he would give him the area of land he had covered. 27 enough, the horseman quickly jumped onto his horse and 28 as fast as possible to cover as much land area as he could. He 29 riding and riding, whipping the horse to go as fast as possible. Even when he was 30 or tired, he did not stop 31 he wanted to cover as much area as possible. When he at last covered a large amount of land, he was exhausted and was 32 . Then he asked himself, “Why did I33 myself so hard to cover so much land area? Now I am dying and I only 34 a very small area to 35 myself.” The above story is 36 to the journey of our 37 . We push ourselves very hard every day to make more 38 , to gain power or recognition. We neglect(疏忽,忘记) our 39 , time with our family and to appreciate(欣赏) the surrounding 40 and the things we love to do. One day 41 we look back, we will 42 that we don’t really need that much, 43 then we cannot turn back time for what we have 44 . Life is not about making money. Life is definitely(肯定地) not about work! Work is only 45 to keep us living so as to enjoy the beauty and pleasures of life.
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某化学课外活动小组通过实验研究NO2的性质.
已知:2NO2+2NaOH═NaNO3+NaNO2+H2O
任务1:利用图1所示装置探究NO2能否被NH3还原(K1、K2为止水夹,夹持固定装置略去).
(1)A装置中制取NH3反应的化学方程式是______.
(2)若NO2能够被NH3还原,预期观察到C装置中的现象是______.
(3)实验过程中,未能观察到C装置中的预期现象.该小组同学从反应原理的角度分析了原因,认为可能是:
①NH3还原性较弱,不能将NO2还原;
②在此条件下,NO2的转化率极低;
③______.
(4)此实验装置存在一个明显的缺陷是______.
任务2:探究NO2能否与Na2O2发生氧化还原反应.
(5)实验前,该小组同学提出三种假设.
假设1:二者不反应;
假设2:NO2能被Na2O2还原;
假设3:______.
(6)为了验证假设3,该小组同学选用任务1中的B、D、E装置,将B中的药品更换为Na2O2,另选F装置(如图2所示),重新组装,进行实验.
①装置的合理连接顺序是(某些装置可以重复使用)______.
②实验过程中,B装置中淡黄色粉末逐渐变成白色.经检验,该白色物质为纯净物,且无其他物质生成.推测B装置中反应的化学方程式为______.
鉴别人禽流感与流感病毒性肺炎的主要依据是()
A.流行病学史
B.高热、咳嗽等临床表现
C.血常规检查
D.X线胸片
E.病原学检查
()渔民开捕祭祀大典已经沿袭了5000多年历史。
A.太湖
B.鄱阳湖
C.洪泽湖
D.巢湖