【简答题】完形填空。 When I was about 12, a girl in my class liked to point out my problems. I was too thin; I wasn't a good student; I talked too much, I was too 1 , and so on. At last, I became very angry and ran ...
【单选题】已知B、C为常见的两种金属单质,E、I为常见的两种非金属单质,A为硫酸盐反应②为D的溶液与C在加热条件下的反应,P溶液和G溶液中具有相同的阳离子,请根据要求回答下列问题. (1)B元素在周期表的位置:______, (2)物质I的电子式:______. (3)Y转变为X的现象是:______.涉及的反应方程式为:______. (4)写出反应④的化学反应方程式:______.物质F与HI水溶液的离...
D.
能透过半透膜,不能透过滤纸 (6)向含1molG的溶液中加入1molNa 2 O 2 ,所发生的离子反应方程式:______.
【简答题】I can well remember that I was once asked to deliver a speech titled—A Real Test in My Life before the whole class at the age of 9! You can imagine how 1. (terrible)shy I was the moment I thought of ...
【多选题】以下印刷或印后工艺,能明显改善或改变印刷品光泽度和物理性能的有
【简答题】(Para.3) And so it is with all major news stories. I remember when I was at primary school the teacher announcing pale-faced to a startled class of seven-year-olds President Kennedy is dead. I didn't ...
【单选题】下列关于分散系概念的描述,正确的是()
F.
下列哪种体系的分散相粒子能透过滤纸而不能透过半透膜( )
J.
都不是 K. :C L. 下列几种分散系中能发生丁达尔现象的是( )
【单选题】下列关于蛋白质的叙述中,不正确的是 [ ] ①蛋白质溶液中加入饱和硫酸铵溶液后,蛋白质析出。虽再加水,也不溶解 ②人工合成的具有生命活力的蛋白质--结晶牛胰岛素是我国科学家在1965年首次合成的 ③重金属盐能使蛋白质凝结,所以误食可溶性重金属盐会中毒 ④浓硝酸溅在皮肤上,使皮肤呈黄色是由于浓硝酸和蛋白质发生了颜色反应 ⑤蛋白质分子能透过滤纸,但不能透过半透膜 ⑥天然蛋白质的最终水解产物是α...
【简答题】纳米科技是21世纪经济发展的发动机。人们会利用纳米级(1~100 nm,1 nm=10-9 m)微粒物质制造出更加优秀的材料和器件,使化学在材料、能源、环境和生命科学等领域发挥越来越重要的作用。 (1)下列分散系的分散质与纳米级微粒在直径上具有相同数量级的是 [ ] A.溶液 B.胶体 C.悬浊液 D.乳浊液 (2)将纳米级微粒物质溶解于液体溶剂中形成一种分散系,对该分散系及分散质颗粒的叙...
【简答题】I used to be a very self centered person , but in the past two years I have really changed.I have started to think about other people 1 I think about myself.I am happy that I am becoming a 2 person....